编号 开局名称 步子
A12 A12 1.c4 c6 2.Nf3 d5 3.b3
A14 A14 1.c4 e6 2.Nf3 d5 3.g3 Nf6 4.Bg2 Be7
A16 A16 1.c4 Nf6 2.Nc3
A33 A33 1.c4 c5 2.Nf3 Nf6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Nc6
A42 A42 1.d4 d6 2.c4
A59 A59 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6 Bxa6 6.Nc3 d6 7.e4
A61 A61 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3
A62 A62 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.g3
A63 A63 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.g3 Bg7 8.Bg2 O-O 9.O-O a6
A64 A64 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.g3 Bg7 8.Bg2 O-O 9.O-O a6 10.a4 Nbd7 11.Nd2
A68 A68 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Nf3
A69 A69 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Nf3 O-O 9.Be2 Re8
A71 A71 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Bg5
A72 A72 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2
A73 A73 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O
A74 A74 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O a6
A77 A77 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O Re8 10.Nd2
A78 A78 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O Re8 10.Nd2 Na6
A79 A79 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O Re8 10.Nd2 Na6 11.f3
A84 A84 1.d4 f5 2.c4
A85 A85 1.d4 f5 2.c4 g6 3.Nc3
A87 A87 1.d4 f5 2.c4 Nf6 3.g3 g6 4.Bg2 Bg7 5.Nf3
A90 A90 1.d4 f5 2.c4 Nf6 3.g3 e6
A91 A91 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7
A92 A92 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3
A94 A94 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d5 7.b3 c6
A95 A95 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d5 7.Nc3
A96 A96 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d6
A98 A98 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d6 7.Nc3 Qe8 8.Qc2
A99 A99 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d6 7.Nc3 Qe8 8.b3
B00 Aachen Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.exd5 Nb4
A00 Aasum Gambit; Hector Gambit 1.Nc3 d5 2.e4 dxe4 3.Bc4
C36 Abbazia Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 d5 4.exd5 Nf6
A06 Abonyi Gambit; Tennison Gambit; Lemberg Gambit; Zukertort Gambit 1.Nf3 d5 2.e4
A52 Abonyi Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.e4 Nxe5 5.f4 Nec6
B20 Abrahams Variation, Sicilian Wing Gambit 1.e4 c5 2.b4 cxb4 3.Bb2
D31 Abrahams; Noteboom; Klaus Junge Var, QGD 1.d4 d5 2.c4 e6 3.Nc3 c6 4.Nf3 dxc4 5.a4 Bb4 6.e3 b5 7.Bd2 a5
E70 Accelerated Averbakh Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Bg5
B34 Accelerated Dragon; Fianchetto Var; B34 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6
D28 Accelerated Fianchetto, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2 b5
B06 Accelerated Gurgenidze 1.e4 g6 2.d4 Bg7 3.Nf3 d6 3.Nc3 c6
B27 Accelerated Paulsen, Sicilian 1.e4 c5 2.Nf3 Qc7
D81 Accelerated Russian Variation, Grunfeld; D81 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Qb3
E24 Accelerated Saemisch Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3
B41 Accelerated Wimpy Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4
D45 Acclerated Meran, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 a6
B27 Action Extension, Sicilian 1.e4 c5 2.Nf3 g6 3.c4 Bh6
C81 Adam Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Qe2 Be7 10.c4
B90 Adams Attack, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.h3
B00 Adams Defense 1.e4 Nh6
C27 Adams Gambit, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Qh5 Nd6 5.Bb3 Nc6 6.d4
A52 Adler Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Nf3
D70 Adjorjan Gambit 1.d4 Nf6 2.c4 g6 3.d5 b5
A10 Adorjan System, English 1.c4 g6 2.e4 e5
D15 Advance System, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 c5
B12 Advance Variation, Caro 1.e4 c6 2.d4 d5 3.e5  
C02 Advance Variation, French; C02 1.e4 e6 2.d4 d5 3.e5
B29 Advance Variation, Sicilian 1.e4 c5 2.Nf3 Nf6 3.e5
D34 Advance Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.Bg5 c4
C02 Advance; Nimzovich; Steinitz Var, Fr 1.e4 e6 2.d4 d5 3.e5 Bd7
A13 Agincourt Variation, English 1.c4 e6 2.Nf3 d5 3.g3
A53 Aged Gibbon Gambit 1.d4 Nf6 2.c4 d6 3.g4
A13 Agincourt; Kurajica Defense, English; A13 1.c4 e6
A00 Akahi Variation 1.e3 e5 2.Nc3 Nf6 3.f4 exf4 4.Nf3
C60 Alapin Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bb4
B20 Alapin Formation, Smith-Morra Declined, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 Nf6
C60 Alapin Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bb4 4.c3 Ba5 5.Bxc6 dxc6
C68 Alapin Gambit, Ruy Lopez Exchange 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.O-O Bg4 6.h3 h5
C20 Alapin Opening 1.e4 e5 2.Ne2
C14 Alapin Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7 7.Nb5
D08 Alapin Variation, QGD 1.d4 d5 2.c4 e5 3.dxe5 d4 4.Nf3 Nc6 5.Nbd2
D31 Alapin Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 b6
C73 Alapin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.Bxc6+ bxc6 6.d4 f6
D16 Alapin Variation, Slav; D16 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4
C25 Alapin Variation, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4
B22 Alapin; Sveshnikov Var, Sicilian; B22 1.e4 c5 2.c3
A80 Alapin; Ulvestad; Manhattan; Kmoch Variation, Dutch 1.d4 f5 2.Qd3  
C00 Alapin; Witaker Gambit, French 1.e4 e6 2.d4 d5 3.Be3
C41 Alapin-Blackburne Gambit, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Bg4 4.dxe5 Nd7
C00 Alapin-Diemer Gambit, French 1.e4 e6 2.d4 d5 3.Be3 dxe4 4.f3
C70 Alapin's Defense Deferred, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Bb4
D44 Alatortsev System, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.Nxg5 Nd5
D31 Alatortsev; Petrosian, Charousek Var, QGD 1.d4 d5 2.c4 e6 3.Nc3 Be7
D08 Albin Countergambit; Cavalotti Var, QGD; D08 1.d4 d5 2.c4 e5
C53 Albin Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.O-O
C14 Albin-Chatard Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4 Bxg5 7.hxg5 Qxg5
D00 Albrecht; Karlshruhle Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 g6
D00 Alburt Defense, QP 1.d4 d5 2.Nc3 Bf5
B04 Alburt Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 g6
C15 Alekhine (Maroczy) Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Ne2
D10 Alekhine Attack, Slav 1.d4 d5 2.c4 c6 3.Nc3 dxc4 4.e4
D06 Alekhine Defense, QGD 1.d4 d5 2.c4 g6 
D51 Alekhine Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.Nf3 h6 6.Bh4 dxc4
C45 Alekhine Gambit, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.e5
B74 Alekhine Line, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O O-O 9.Nb3 a5
D28 Alekhine System, Classical Defense, QGA; D28 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2
D20 Alekhine System, QGA 1.d4 d5 2.c4 dxc4 3.e4 Nf6
B05 Alekhine Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Bg4 5.c4
E03 Alekhine Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Qa4+ Nbd7 6.Qxc4 a6 7.Qc2
D06 Alekhine Variation, Chigorin Defense 1.d4 d5 2.c4 Nc6 3.Nf3 Bg4 4.Qa4
A92 Alekhine Variation, Dutch 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O Ne4
D21 Alekhine Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 a6
D22 Alekhine Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 a6 4.e3 Bg4
D67 Alekhine Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5 10.Bxe7 Qxe7 11.Ne4 
D51 Alekhine Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.Nf3 c6 6.e4
D38 Alekhine Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 Bb4 5.Qa4
B70 Alekhine Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be2 Bg7 7.O-O O-O 8.Nb3
D15 Alekhine Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.e3
D15 Alekhine Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.e3 b5 6.a4 b4
C27 Alekhine Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Qh5 Nd6 5.Bb3 Be7 6.Nf3 Nc6 7.Nxe5
B02 Alekhine's Defense; B02 1.e4 Nf6  
C68 Alekhjne Variation, Ruy Lopez Exchange 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.d4 exd4 6.Qxd4 Qxd4 7.Nxd4 Bd6
B00 Alekseev Variation, Nimzovich; Heinola-Deppe Gambit 1.e4 Nc6 2.d4 d5 3.Nc3 e5
A00 Alessi Gambit, Grob 1.g4 f5
C53 Alexandre Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 f5
C39 Allgaier; Cotter Cambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5
B27 Althouse; Stiletto Variation, Sicilian 1.e4 c5 2.Nf3 Qa5
A00 Alua Variation 1.e3 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3
A00 Amar; Paris Opening 1.Nh3
D00 Amazon Attack 1.d4 d5 2.Qd3
A00 Amazon, Dunst 1.Nc3 d5 2.e4 dxe4 3.Nxe4 Qd5
B45 American Attack, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Nf6 6.Ndb5 Bb4 7.Nd6+
A82 American Gambit, Dutch 1.d4 f5 2.e4 fxe4 3.Nd2
A06 Ampel Variation, Reti 1.Nf3 d5 2.Rg1
B72 Amsterdam (Battery) Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.Qd2
A00 Amsterdam Attack 1.e3 e5 2.c4 d6 3.Nc3 Nc6 4.b3 Nf6
B93 Amsterdam Variation, Sicilian; B93 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.f4
D12 Amsterdam Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5 5.cxd5 cxd5 6.Nc3
C14 Anderssen (Richter) Attack, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.Bxf6
C37 Anderssen Counter-Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5 Qh4+ 6.Kf1 Nh6 7.d4 d6
C33 Anderssen Defense, KGA 1.e4 e5 2.f4 exf4 3.Bc4 g5
C39 Anderssen Defense, Kieseritsky Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6
C25 Anderssen Defense, Vienna 1.e4 e5 2.Nc3 Bc5
C23 Anderssen Gambit 1.e4 e5 2.Bc4 b5 3.Bxb5 c6
B01 Anderssen Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 e5
C51 Anderssen Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Be7
C77 Anderssen Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d3
C65 Anderssen Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d3 d6 5.Bxc6+
B41 Anderssen; Counterattack Var, Sic 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6
C39 Anderssen-Cordel Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.d4 Nh5 9.Bxf4 Nxf4
A00 Anderssen's Opening 1.a3
A00 Andersspike 1.a3 g6 2.g4
B20 Andreaschek Gambit, Sicilian 1.e4 c5 2.d4 cxd4 3.Nf3 e5 4.c3
A10 Anglo Scandanavian Defense, English 1.c4 d5
A15 Anglo System, English; A15 1.c4 Nf6
A21 Anglo-Dutch 1.c4 e5 2.Nc3 f5
A10 Anglo-Dutch Defense 1.c4 f5
A10 Anglo-Lithuanian Variation, English 1.c4 Nc6
A10 Anglo-Polish Dutch 1.c4 f5 2.b4
A41 Anglo-Slav Opening 1.d4 c6 2.c4 d6
A11 Anglo-Slav, English; A11 1.c4 c6
A16 Anti-anti-grunfeld 1.c4 Nf6 2.Nc3 g6 3.Nf3 Bg7 4.e4
A31 Anti-Benoni Variation, Symmetrical English; A31 1.c4 c5 2.Nf3 Nf6 3.d4
A80 Anti-Classical Line, Dutch 1.d4 f5 2.Qd3 e6 3.g4
B90 Anti-English, Najdorf Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 Ng4
D70 Anti-Grunfeld Variation 1.d4 Nf6 2.c4 g6 3.d5   
A80 Anti-Leningrad Variation, Dutch 1.d4 f5 2.Qd3 g6 3.g4
C88 Anti-Marshall Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.a4
D43 Anti-Meran Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5
B06 Anti-Modern 1.e4 g6 2.d4 Bg7 3.Nc3 d6 4.Bc4 c6 5.Qe2
A80 Anti-Modern, Dutch 1.d4 f5 2.Qd3 d6 3.g4
D44 Anti-Moscow Gambit 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 h6 6.Bh4
E10 Anti-Nimzo-Indian; E10 1.d4 Nf6 2.c4 e6 3.Nf3
D30 Anti-Noteboom Gambit, Semi-Slav 1.d4 d5 2.c4 e6 3.Nf3 c6 4.Nc3 dxc4 5.g3
D31 Anti-Noteboom Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.Nf3 dxc4 5.Bg5
B07 Anti-Philidor 1.e4 d6 2.d4 Nf6 3.Nc3 Nbd7 4.f4
A00 Anti-Pirc Variation, Dunst; Myers Attack 1.Nc3 g6 2.h4
E17 Anti-Queen's Indian System 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.Nc3
B57 Anti-Sozin Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bc4 Qb6
A80 Anti-Stonewall, Dutch 1.d4 f5 2.Qd3 d5 3.g4
D55 Anti-Tartakower Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bxf6
D02 Anti-Torre 1.d4 d5 2.Nf3 Bg4 3.Ne5 Bf5 4.g4
D02 Anti-Torre, QP 1.d4 d5 2.Nf3 Bg4
D00 Anti-Veresov 1.d4 d5 2.Nc3 Bg4
D10 Anti-Winawer Gambit, Slav 1.d4 d5 2.c4 c6 3.Nc3 e5 4.e4
A81 Antoshin-Hort Variation, Dutch 1.d4 f5 2.g3 Nf6 3.Bg2 d6
A45 Arafat Gambit 1.d4 Nf6 2.e4 Nxe4 3.Bd3 Nf6 4.Bg5
B98 Argenitne; Goteborg Var, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7 8.Qf3 h6 9.Bh4 g5
A75 Argentine Attack, Benoni; A75 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O a6 10.a4 Bg4
D52 Argentine Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nf3 Qa5 7.Nd2 Bb4 8.Qc2 O-O 9.Bh4
D31 Argentinian Gambit, QGD 1.d4 d5 2.c4 Bf5 3.cxd5 Bxb1 4.Qa4+ c6 5.dxc6 Nxc6 6.Rxb1 Qxd4
C78 Arkangelsk; Counterthrust Var, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 
C18 Armenian Line, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3 Ba5 6.b4 cxd4
B28 Aronin System, Sicilian 1.e4 c5 2.Nf3 a6 3.Be2
E97 Aronin-Taimanov Variation, KID; E97 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6
C95 Arseniev Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8 10.d4 Nbd7 11.c4
A34 Asymmetrical Variation, English 1.c4 c5 2.Nc3 Nf6 3.Nf3 d5 4.cxd5 Nxd5
B01 Atkinson (Kloosterboer) Variation, Center Counter 1.e4 d5 2.exd5 c6 3.dxc6 e5
C37 Australian Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.h4
B09 Austrian Attack, Pirc; B09 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4
D06 Austrian Defense; Summetrical Defense, QGD 1.d4 d5 2.c4 c5
B09 Austrian; Yugoslav Defense, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3
E30 Averbakh Gambit, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Bg5 h6 5.Bh4 c5 6.d5 b5
E73 Averbakh Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5
A41 Averbakh Variation, Modern 1.d4 g6 2.c4 Bg7 3.Nc3 d6 4.e4
E14 Averbakh Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.e3 Bb7 5.Bd3 c5 6.O-O Be7 7.b3 O-O 8.Bb2 cxd4 9.Nxd4
C87 Averbakh Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 d6
B03 B03 1.e4 Nf6 2.e5 Nd5 3.d4
B04 B04 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3
B05 B05 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Bg4
B07 B07 1.e4 d6
B08 B08 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3
B11 B11 1.e4 c6 2.Nc3
B12 B12 1.e4 c6 2.d4
B14 B14 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nc3
B15 B15 1.e4 c6 2.d4 d5 3.Nc3
B19 B19 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Bf5 5.Ng3 Bg6 6.h4 h6 7.Nf3
B25 B25 1.e4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6
B26 B26 1.e4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 6.Be3
B27 B27 1.e4 c5 2.Nf3
B31 B31 1.e4 c5 2.Nf3 Nc6 3.Bb5 g6
B32 B32 1.e4 c5 2.Nf3 Nc6 3.d4
B33 B33 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6
B35 B35 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.Nc3 Bg7 6.Be3 Nf6 7.Bc4
B37 B37 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.c4 Bg7
B38 B38 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.c4 Bg7 6.Be3
B41 B41 1.e4 c5 2.Nf3 e6 3.d4
B42 B42 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Bd3
B43 B43 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Nc3
B45 B45 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3
B46 B46 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 a6
B48 B48 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Qc7 6.Be3
B49 B49 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Qc7 6.Be3 a6 7.Be2
B53 B53 1.e4 c5 2.Nf3 d6 3.d4
B54 B54 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4
B55 B55 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6
B56 B56 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3
B58 B58 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Be2
B59 B59 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Be2 e5 7.Nb3
B61 B61 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Qd2
B62 B62 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6
B64 B64 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 Be7 8.O-O-O O-O 9.f4
B65 B65 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 Be7 8.O-O-O O-O 9.f4 Nxd4 10.Qxd4
B66 B66 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 a6
B67 B67 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 a6 8.O-O-O Bd7
B68 B68 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 a6 8.O-O-O Bd7 9.f4 Be7
B69 B69 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 a6 8.O-O-O Bd7 9.f4 Be7 10.Nf3 b5 11.Bxf6
B72 B72 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3
B73 B73 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O
B74 B74 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O O-O 9.Nb3
B75 B75 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3
B77 B77 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4
B78 B78 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 Bd7 10.O-O-O
B79 B79 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 Bd7 10.O-O-O Qa5
B85 B85 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be2 a6 7.O-O Be7
B89 B89 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4 Nc6 7.Be3  
B94 B94 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5
B95 B95 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6
B96 B96 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4
B98 B98 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7
B99 B99 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7 8.Qf3 Qc7 9.O-O-O Nbd7
D17 Baarn Variation, Slav; Bled Attack 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Nh4
C01 Baeuerle Gambit, French 1.e4 e6 2.d4 b5
C37 Baldwin Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6 7.Nc3 Qd4+ 8.Kh1 Qxc4 9.Nd5
C90 Balla Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 Na5 9.Bc2 c5 10.d4 Qc7
A82 Balogh Defense, Dutch 1.d4 f5 2.e4 d6
B07 Balogh Defense, Pirc 1.e4 d6 2.d4 f5
B03 Balogh Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Bc4
A52 Balogh; Tartakower C-G, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.e4 d6
D31 Baltic Defense, QGD 1.d4 d5 2.c4 Bf5 3.cxd5 Bxb1 4.Qa4+ c6 5.dxc6 Nxc6
C00 Banzai-Leong Gambit, French 1.e4 e6 2.b4
B28 Barcza Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c3 Nf6
A07 Barcza Opening, Reti; King's Indian Attack; A07 1.Nf3 d5 2.g3
A80 Barcza Variation, Dutch 1.d4 f5 2.Nf3 Nf6 3.c3
C44 Bardeleben Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.c3 dxc3 5.Nxc3 Bb4 6.Bc4 Nf6
C29 Bardeleben Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.Qf3 f5
C68 Barendregt-Fischer Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.O-O
B22 Barmen Defense, Sicilian 1.e4 c5 2.c3 d5 3.exd5 Qxd5
A52 Barmina Gambit, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.e4 Nxe5 5.f4 Bc5
B00 Barnes Defense 1.e4 f6
A00 Barnes; Gedult-Gunderam; Walkerling 1.f3  
C60 Barnes; Smyslov; Fianchetto Var, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 g6
D02 Barry Attack 1.d4 Nf6 2.Nf3 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O 6.Be2
B00 Basman Defense; Macho Grob 1.e4 g5
C44 Basman Gambit 1.e4 e5 2.Nf3 Nc6 3.Be2 Nf6 4.d4 exd4 5.e5
A00 Basman Gambit, Grob 1.g4 d5 2.Bg2 h5 3.gxh5
C33 Basman Gambit, KGA 1.e4 e5 2.f4 exf4 3.Qe2
A81 Basman Variation, Dutch 1.d4 f5 2.g3 g6 3.Bg2 Bg7 4.Nf3 c6 5.O-O Nh6
B00 Basman; Macho Grob; Borg 1.e4 g5  
B50 Basman-Palatnik Gambit 1.e4 c5 2.Nf3 d6 3.c3 Nf6 4.Be2 Nc6 5.d4 cxd4 6.cxd4 Nxe4
C84 Basque Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.d4 exd4 7.e5 Ne4 8.c3
A45 Basque Opening 1.d4 Nf6 2.b3
B47 Bastrikov Variation, Sicilian; B47 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Qc7
A02 Batavo Polish Attack, Bird 1.f4 Nf6 2.Nf3 g6 3.b4
A00 Battambang, Dunst 1.Nc3 e5 2.a3
C20 Bavarian Gambit 1.e4 e5 2.c4 d5
E97 Bayonet Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.b4
B07 Bayonet Attack, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Be2 Bg7 5.h4
B12 Bayonet Variation, Caro 1.e4 c6 2.d4 d5 3.e5 Bf5 4.g4
C77 Bayreuth Variation, ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.Bxc6
C34 Becker; Anti-Kieseritzky Var, KGA 1.e4 e5 2.f4 exf4 3.Nf3 h6
A10 Beefeater 1.c4 g6 2.Nc3 Bg7 3.d4 c5 4.d5 Bxc3 5.bxc3 f5
A40 Beefeater Variation 1.d4 g6 2.c4 Bg7 3.Nc3 c5 4.d5 Bxc3+ 5.bxc3 f5
D50 Been & Koomen; Dutch & Peruvian 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 c5
C47 Belgrade Gambit, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 exd4 5.Nd5
E35 Beliavsky Gambit, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.cxd5 exd5 6.Nf3 Qf5 7.Qd1 e5
D31 Beliavsky Line, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.Nf3 dxc4 5.Bg5 f6
C37 Bello Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6 7.Nc3
A84 Bellon Gambit 1.d4 e6 2.c4 f5 3.e4
A84 Bellon Gambit, Dutch 1.d4 f5 2.c4 e6 3.e4
A22 Bellon Gambit, English 1.c4 e5 2.Nc3 Nf6 3.Nf3 e4 4.Ng5 b5
C64 Benelux Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.c3 Nf6 5.d4 Bb6 6.O-O O-O
C44 Benima Defense, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Be7
E62 Benjamin Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c6 7.O-O Qb6
E99 Benko Attack, KID; E99 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Ne1 Nd7 10.f3
A57 Benko Gambit Accepted 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5
A57 Benko Gambit Declined; Hjoerring Countergambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.e4
A57 Benko Gambit; Volga; Opocensky; Vaitonis; A57 1.d4 Nf6 2.c4 c5 3.d5 b5
E99 Benko Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Ne1 Nd7 10.f3 f5 11.g4
A00 Benko; Barczay; Bilek; Hungarian 1.g3  
E74 Benoni Defense, KID; E74 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 c5
E31 Benoni Defense, Nimzo-Indian; E31 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Bg5 h6 5.Bh4 c5 6.d5 d6
A43 Benoni Gambit Accepted 1.d4 c5 2.dxc5
A09 Benoni Reversed; Wing Blumenfeld; Advance Variation 1.Nf3 d5 2.c4 d4  
A43 Benoni-Indian Defense 1.d4 c5 2.d5 Nf6
A43 Benoni-Staunton Gambit 1.d4 c5 2.d5 f5 3.e4
A47 Berg Variation 1.d4 Nf6 2.Nf3 b6 3.g3 Bb7 4.Bg2 c5 5.c4 cxd4 6.Qxd4
C63 Berger (Dyckhoff) Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3  
C22 Berger Variation, Center 1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qe3 Nf6  
C42 Berger Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Be7 7.O-O Nc6 8.Re1 Bg4 9.c3 f5 10.Nbd2
C80 Berger Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.a4 Nxd4 9.Nxd4 exd4 10.Nc3
C24 Berlin Defense, Bishop; C24 1.e4 e5 2.Bc4 Nf6  
C39 Berlin Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6
C65 Berlin Defense, Ruy Lopez; C65 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6
A00 Berlin Gambit, Dunst 1.Nc3 Nc6 2.d4 d5 3.e4 dxe4 4.d5
E38 Berlin Variation, Nimzo-Indian; E38 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 c5
C82 Berlin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Nc5
C67 Berlin; Rio de Janerio Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 Nd6 7.Bxc6+ bxc6 8.dxe5 Nb7 9.Nc3 O-O 10.Re1
C57 Berliner Variation, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nd4 6.c3 b5 7.Bf1 Nxd5 8.Ne4 Qh4
E53 Bernstein Defense; Gligoric System; E53 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5
C49 Bernstein Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Bg5 Bxc3 8.bxc3 Ne7
C12 Bernstein Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Bh4
E56 Bernstein Variation, Nimzo-Indian; E56 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O Nc6
D57 Bernstein Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 Ne4 8.Bxe7 Qxe7 9.cxd5 Nxc3 10.bxc3
C80 Bernstein Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Nbd2
C35 Bertin; Three Pawns Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Be7 4.Bc4 Bh4+ 5.g3
D01 Betbeder; Veresov; Levitzky; Parisian 1.d4 d5 2.c4 dxc4 3.e4 f5
C65 Beverwijk Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Bc5
C21 Beyer Gambit 1.e4 e5 2.d4 d5
B20 Big Clamp Variation, Sicilian 1.e4 c5 2.d3 Nc6 3.c3 d6 4.f4
B00 Bileefelder Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 Bc5
C40 Bilguer Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4
C33 Bilguer-Mirage Variation, KGA 1.e4 e5 2.f4 exf4 3.Qe2
D20 Billinger Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e3 e5 4.Bc4 exd4 5.Qb3 Qe7 6.a3
A00 Billockus-Johansen Gambit, Dunst 1.Nc3 e5 2.Nf3 Bc5
C54 Bird Attack, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.b4
C61 Bird Defense, Ruy Lopez; C61 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nd4
C37 Bird Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.d4 Bg4 5.Ne5 Qh4+ 6.g3
C41 Bird Gambit, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4 4.c3
C00 Bird Invitation, French 1.e4 e6 2.Bb5
B33 Bird Variation, Siclian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 Be6
A02 Bird's Opening; Dutch Attack 1.f4
A00 Birmingham Gambit, Polish 1.b4 c5
B06 Bishop Attack 1.e4 g6 2.d4 Bg7 3.Bc4
A57 Bishop Attack, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.Bg5
E47 Bishop Attack, Nimzo-Indian; E47 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3
D30 Bishop Attack, Tarrasch 1.d4 d5 2.c4 e6 3.Nf3 c5 4.cxd5 exd5 5.Bg5
D00 Bishop Attack; Levitsky Attack, Queen Pawn Game 1.d4 d5 2.Bg5
D04 Bishop Defense, QP; Anti-Colle 1.d4 d5 2.Nf3 Nf6 3.e3 Bf5
C27 Bishop Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Bc5
C33 Bishop's Gambit, KGA 1.e4 e5 2.f4 exf4 3.Bc4
C23 Bishop's Opening; C23 1.e4 e5 2.Bc4
C37 Blachy Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Nc6
C31 Blackbunre Attack, KGD 1.e4 e5 2.f4 d5 3.Nf3
B01 Blackbunre-Kloosterboer Gambit, Center Counter 1.e4 d5 2.exd5 c6 3.dxc6 e5
C49 Blackburne Attack, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.Nd5 Bc5 7.d4
A91 Blackburne Attack, Dutch 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Bg7 5.Nh3
C45 Blackburne Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.c3 Nge7 7.Qd2
C10 Blackburne Defense, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7
B01 Blackburne Gambit, Center Counter 1.e4 d5 2.exd5 c6 3.dxc6 Nxc6
A81 Blackburne Variation, Dutch 1.d4 f5 2.g3 Nf6 3.Bg2 e6 4.Nh3
D21 Blackburne's Move, QGA; Normal Variation, QGA; D21 1.d4 d5 2.c4 dxc4 3.Nf3
D00 Blackmar Gambit; Gedult Gambit 1.d4 d5 2.e4 dxe4 3.f3 
D00 Blackmar-Diemer Gambit 1.d4 d5 2.e4
D00 Blackmar-Diemer Gambit 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3
A45 Blackmar-Diemer Gambit Deferred 1.d4 Nf6 2.f3 d5 3.e4  
A80 Blackmar's Second Gambit, Dutch 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.f3
A85 Bladel Variation, Dutch 1.d4 f5 2.c4 g6 3.Nc3 Nh6
C23 Blanel Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.Nc3 Nxe4
A12 Bled Variation, English 1.c4 c6 2.Nf3 d5 3.b3 Nf6 4.g3 g6
C33 Bledow Countergambit, KGA 1.e4 e5 2.f4 exf4 3.Bc4 d5 4.Bxd5 Nf6
C33 Bledow; Morphy Defense, KGA 1.e4 e5 2.f4 exf4 3.Bc4 d5
A44 Blockade Variation; Semi-Benoni; Russian Variation 1.d4 c5 2.d5 e5 3.e4 d6
A06 Bloodgood Gambit, Reti 1.Nf3 d5 2.b3 c5 3.e4 dxe4 4.Ne5
E10 Blumenfeld Countergambit 1.d4 Nf6 2.c4 e6 3.Nf3 c5 4.d5 b5
E10 Blumenfeld Countergambit Accepted 1.d4 Nf6 2.c4 e6 3.Nf3 c5 4.d5 b5 5.dxe6 fxe6 6.cxb5 d5
A09 Blumenfeld Gambit, Reti 1.Nf3 d5 2.c4 d4 3.e3 c5 4.b4
E10 Blumenfeld Variation 1.d4 Nf6 2.c4 e6 3.Nf3 c5
D49 Blumenfeld Variation, QGD; D49 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 c5 10.e5 cxd4 11.Nxb5
C45 Blumenfeld Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.Nb5
E81 Bobotsov-Korchnoi-Petrosian Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Nge2
C33 Boden Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 Nc6
C41 Boden Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4 4.Qxd4 Bd7
C64 Boden Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.c3 Qe7
C42 Boden-Kieseritzky Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Bc4 Nxe4 4.Nc3
C27 Boden-Kieseritzky Gambit, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Nf3
B01 Boehnke Gambit Accepted, Center Counter 1.e4 d5 2.exd5 e5 3.dxe6 Bxe6
B01 Boehnke Gambit, Center Counter 1.e4 d5 2.exd5 e5
D52 Bogoljubov Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nf3 Qa5 7.Nd2 Bb4 8.Qc2
C33 Bogoljubov; Jaenisch Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Nf6 4.Nc3 c6
A40 Bogoljubov; Mikenas-Van Geet Defense 1.d4 Nc6
C47 Bogoljubow (Scotch) Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4
D24 Bogoljubow Defense, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.Nc3 a6 5.e4
E11 Bogoljubow Defense; Bogo-Indian Defense; E11 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+
D00 Bogoljubow Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6
C17 Bogoljubow Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.Bd2
C33 Bogoljubow Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Nf6 4.Nc3
B00 Bogoljubow Variation, Nizovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3
D46 Bogoljubow Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 Be7
A09 Bogoljubow Variation, Reti 1.Nf3 d5 2.c4 c6 3.b3
D34 Bogoljubow Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.Bg5 Be6 10.Rc1 c4
C58 Bogoljubow Variation, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Qf3
C91 Bogoljubow; Counterthrust Var, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.d4 Bg4
C11 Boleslavsky Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.f4 c5 6.Nf3 Nc6 7.Be3
B58 Boleslavsky Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Be2 e5
D11 Bonet Gambit, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Bg5
C34 Bonsch-Osmolovsky Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Ne7
A51 Bonsdorf Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ne4 4.a3 b6
B00 Borg Defense; Troon Gambit 1.e4 g5 2.d4 h6 3.h4 g4
A40 Borg Gambit 1.d4 g5
B00 Borg Gambit 1.e4 g5 2.d4 Bg7
A45 Borg Variation, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.Bf4 g5
C96 Borisenko Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Nc6
C95 Borisenko Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8 10.d4 Nbd7
D22 Borisenko-Furman Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 a6 4.e4
B25 Botvinnik Defense, Sicilian Closed 1.e4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 6.f4 e5
A28 Botvinnik Line, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.e4
A36 Botvinnik System Reversed, Symmetrical English 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.e3 e5
A25 Botvinnik System, King's English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 6.e4
E49 Botvinnik System, Nimzo-Indian; E49 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.a3 Bxc3+ 7.bxc3
E07 Botvinnik Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Nc3 c6 8.Qd3
A93 Botvinnik Variation, Dutch; A93 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d5 7.b3
A25 Botvinnik Variation, English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.e4
C06 Botvinnik Variation, French 1.e4 e6 2.d4 d5 3.Nd2 Nc6 4.e4 Nfd7 5.Bd3 c5 6.c3 b6
D83 Botvinnik Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O 6.Rc1 c5 7.dxc5 Be6
D80 Botvinnik Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Qb3 e6
E24 Botvinnik Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.f3 d5 7.e3 O-O 8.cxd5 Nxd5
E36 Botvinnik Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Nc6
D60 Botvinnik Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Bd3
D44 Botvinnik Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 dxc4 6.e4 b5
E12 Botvinnik Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb7 5.Bg5 h6 6.Bh4 g5 7.Bg3 Nh5
A36 Botvinnik Variation, Symmetrical English 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.e4
A91 Botvinnik-Bronstein Variation, Dutch 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nc3 O-O 6.e3
B12 Botvinnik-Carls Defense, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 c5
A00 Bouncing Bishop Variation 1.e3 e5 2.Bc4 b5 3.Bb3
C00 Bourdonnais (La Bourdonnais) Variation, French 1.e4 e6 2.f4  
B32 Bourdonnais; Lowenthal Var, Sic 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e5
B20 Bowlder Attack, Sicilian 1.e4 c5 2.Bc4
D01 Boyce Defense, Veresov 1.d4 d5 2.Nc3 Nf6 3.Bg5 Ne4
C11 Bradford Attack, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.f4 c5 6.dxc5 Bxc5 7.Qg4
A28 Bradley Beach Variation, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.d4 e4
B00 Brandics Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3 a6
C45 Braune Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Be3
A22 Bremen; Carls Variation, English 1.c4 e5 2.Nc3 Nf6 3.g3
A25 Bremen-Hort Variation, English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.e3 d6 6.Nge2 Be6
C37 Brentano Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O d5
C60 Brentano Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 g5
C83 Breslau Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Be7 10.Re1 O-O 11.Nd4
B00 Breyer Defense, Nimzovich 1.e4 Nc6 2.Nc3 Nf6
C44 Breyer Opening, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 Nf6 4.d3 Be7 5.b4
B10 Breyer Variation, Caro-Kann 1.e4 c6 2.d3
C14 Breyer Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4 c5
D03 Breyer Variation, QP 1.d4 d5 2.Nf3 Nf6 3.Bg5 e6 4.e3 c5 5.c3 Qb6
B39 Breyer Variation, Sicilian; B39 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.c4 Bg7 6.Be3 Nf6 7.Nc3 Ng4
D11 Breyer Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nbd2
C29 Breyer Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.Nf3 Be7
C33 Breyer; Hungarian; Carrera, KGA 1.e4 e5 2.f4 exf4 3.Qf3
C94 Breyer; Retreat Variation, Ruy Lopez; C94 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8
B20 Brick Variation, Sicilian 1.e4 c5 2.Nh3
D06 Brieger Defense; Sahovic Defense, QGD; Baltic Defense 1.d4 d5 2.c4 Bf5
D82 Brinckmann Attack, Grunfeld; D82 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4  
A00 Brinckmann Variation, Polish 1.b4 e5 2.Bb2 f6 3.e4 Bxb4 4.Bc4 Nc6 5.f4 Qe7 6.f5 g6
C79 Brix Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O g6
C11 Brodsky-Jones Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.f4 c5 6.dxc5 Nc6 7.a3 Bxc5 8.Qg4 O-O 9.Nf3 f6
D00 Brombacher; Daberitz Var, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 c5
B52 Bronstein (Haag) Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.Bb5+ Bd7 4.Bxd7+ Qxd7 5.O-O Nc6 6.c3 Nf6 7.d4
C40 Bronstein Attack, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Be2
E87 Bronstein Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 Nh5 8.Qd2 Qh4+ 9.g3 Nxg3 10.Qf2 Nxf1
A45 Bronstein Gambit 1.d4 Nf6 2.g4
C40 Bronstein Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Qh5+ g6 7.Qe2
C23 Bronstein Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.Bc4 Nf6 4.f4 Nxe4 5.Nf3
E60 Bronstein Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 c6 7.O-O Qa5
B12 Bronstein Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.Ne2
B01 Bronstein Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd6 4.d4 Nf6 5.Nf3 a6
E80 Bronstein Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 e5 6.d5 Nh5 7.Be3 Na6 8.Qd2 Qh4+ 9.g3 Nxg3 10.Qf2 Nxf1 11.Qxh4 Nxe3 12.Kf2 Nxc4
E48 Bronstein Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.Nf3 c5 7.O-O dxc4 8.Bxc4 Bd7
E48 Bronstein Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.Nf3 c5 7.O-O dxc4 8.Bxc4 Nbd7 9.Ne2
E45 Bronstein Variation, Nimzo-Indian; E45; Byrne Variation 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 b6 5.Ne2 Ba6
E55 Bronstein Variation, Nimzo-Indian; E55 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O dxc4 8.Bxc4 Nbd7
C69 Bronstein Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.O-O Qd6
B41 Bronstein Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.c4 Nf6 6.Nc3 Bb4 7.Bd3 Nc6
C42 Browne Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Be7 7.O-O Nc6 8.c4 Nb4 9.cxd5
B98 Browne Variation, Najdorf Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Be7 8.Qf3 h6 9.Bh4 Qc7
B27 Brussels Gambit, Sicilian 1.e4 c5 2.Nf3 f5
C33 Bryan; Kieseritzky Gambit, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 b5
A00 Bucker Defense, Grob 1.g4 Nh6
A00 Bucker Defense, Polish 1.b4 Na6
B02 Buckley Attack, Alekhine 1.e4 Nf6 2.e5 Nd5 3.Na3
A51 Budapest Defense; A51 1.d4 Nf6 2.c4 e5
B06 Buecker Gambit 1.e4 g6 2.d4 Bg7 3.Bc4 b5
B27 Buecker Variation, Sicilian 1.e4 c5 2.Nf3 h6
E16 Buerger Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 c5 6.d5 exd5 7.Ng5
A00 Bugayev Attack, Polish 1.b4 e5 2.a3
C60 Bulgarian Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a5
A45 Bullfrog; Weidenhagen; Krabbe; Ochsenfrosch 1.d4 Nf6 2.g4
B02 Buntin Gambit, Alekhine 1.e4 Nf6 2.e5 Nd5 3.e6
B00 Burgar Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 d6
E73 Burgess Line, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 Na6 7.Qd2 c6
D94 Burille Variation, Grunfeld; D94 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.e3
C11 Burn Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 dxe4
E81 Byrne Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 c6 7.Bd3 a6
B90 Byrne Variation, Sicilian; English Attack 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3
C01 C01 1.e4 e6 2.d4
C04 C04 1.e4 e6 2.d4 d5 3.Nd2 Nc6
C05 C05 1.e4 e6 2.d4 d5 3.Nd2 Nf6
C06 C06 1.e4 e6 2.d4 d5 3.Nd2 Nf6 4.e5 Nfd7 5.Bd3
C08 C08 1.e4 e6 2.d4 d5 3.Nd2 c5 4.exd5 exd5
C09 C09 1.e4 e6 2.d4 d5 3.Nd2 c5 4.exd5 exd5 5.Ngf3 Nc6
C12 C12 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5
C13 C13 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 dxe4 
C14 C14 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7
C16 C16 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5
C17 C17 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5
C18 C18 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3  
C19 C19 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3 Bxc3+ 6.bxc3 Ne7
C22 C22 1.e4 e5 2.d4 exd4 3.Qxd4
C37 C37 1.e4 e5 2.f4 exf4 3.Nf3 g5
C39 C39 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4
C44 C44 1.e4 e5 2.Nf3 Nc6
C45 C45 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4
C54 C54 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6
C59 C59 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Be2
C72 C72 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.O-O
C73 C73 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.Bxc6+ bxc6
C74 C74 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3
C75 C75 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 Bd7
C76 C76 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 Bd7 6.d4 g6
C77 C77 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6
C82 C82 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3
C83 C83 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Be7  
C87 C87 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1
C88 C88 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3
C89 C89 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3
C90 C90 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6
C92 C92 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3
C95 C95 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8 10.d4
C96 C96 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5
C98 C98 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.Nbd2 Nc6 
C99 C99 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.Nbd2 cxd4
C23 Calabrese Counter-Gambit 1.e4 e5 2.Bc4 f5
B03 Cambridge Gambit, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.c4 Nb6 5.f4 g5
D52 Cambridge Springs; Pillsbury Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nf3 Qa5
C39 Campbell; Brentano; Morphy Var, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 d5
B15 Campomanes Attack, Caro 1.e4 c6 2.d4 d5 3.Nc3 Nf6
C01 Canal Attack, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.exd5 exd5 5.Bd3 Ne7 6.Qh5
C50 Canal Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d3 Nf6 5.Nc3 d6 6.Bg5
D50 Canal; Venice Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 c5 5.cxd5 Qb6
A45 Canard Attack 1.d4 Nf6 2.f4
A02 Canard Formation; Double Duck 1.f4 f5 2.d4 d5
A40 Cannstatter Variation, Mikenas 1.d4 Nc6 2.c4 e5 3.d5 Nd4
D67 Capablanca Freeing Maneuver, QGD; D67 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5
C10 Capablanca Line, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Nf3 Ngf6 6.Nxf6+ Nxf6 7.Ne5
D83 Capablanca Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O 6.Rc1
A47 Capablanca Variation, Indian Game; A47 1.d4 Nf6 2.Nf3 b6
E26 Capablanca Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.e3 Nc6 7.Bd3 O-O 8.Ne2 b6 9.e4 Ne8
E29 Capablanca Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 O-O 6.e3 c5 7.Bd3 Nc6 8.Ne2 b6 9.e4 Ne8
D63 Capablanca Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 b6 8.cxd5 exd5 9.Bb5
D30 Capablanca Variation, QGD 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nbd2
E16 Capablanca Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Bb4+
A09 Capablanca Variation, Reti 1.Nf3 d5 2.c4 c6 3.b3 Nf6 4.Bb2 Bg4
B14 Carlsbad Line, Caro-Kann 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nc3 Nc6 6.Bg5 e6
A81 Carlsbad Variation, Dutch 1.d4 f5 2.g3 g6 3.Bg2 Bg7 4.Nh3
E62 Carlsbad Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nc6
E23 Carlsbad Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3 c5 5.dxc5 Nc6 6.Nf3 Ne4 7.Bd2 Nxd2
D17 Carlsbad Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Ne5 Nbd7 7.Nxc4 Qc7 8.g3 e5
D34 Carlsbad Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.Bg5
C01 Carlson Gambit, French 1.e4 e6 2.d4 d5 3.Nf3 dxe4 4.Ne5
C44 Caro Variation, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Qa4 Bd7
C70 Caro Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5
B10 Caro-Kann Defense; B10 1.e4 c6  
B00 Carr Defense 1.e4 h6
C33 Carrera Gambit, KGA 1.e4 e5 2.f4 exf4 3.Qh5
E00 Catalan Opening 1.d4 Nf6 2.c4 e6 3.g3
C53 Center Attack, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4
C43 Center Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 exd4 4.e5 Ne4 5.Qxd4
C77 Center Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d4 exd4
C84 Center Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.d4
B01 Center Counter; Scandanavian; B01 1.e4 d5
B20 Center Formation, Smith-Morra Declined, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 e5
C62 Center Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 d6 4.d4 exd4 5.O-O
C21 Center Game Accepted 1.e4 e5 2.d4 exd4
C21 Center Game; C21 1.e4 e5 2.d4  
C53 Center Holding Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Qe7 5.d4 Bb6 
A52 Center Play Variation, Budapest; Alekhine Variation 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.e4
D45 Center Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Qc2 Bd6 7.e4
C79 Central Countergambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O d5
A57 Central Storming Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6 Bxa6 6.Nc3 d6 7.f4
C33 Central; Polerio; Willemson, Steinitz 1.e4 e5 2.f4 exf4 3.d4
A10 Chabanon Gambit, English 1.c4 f5 2.Nf3 d6 3.e4
B23 Chameleon Sicilian 1.e4 c5 2.Nc3 Nc6 3.Nge2
B20 Chameleon Variation, Sicilian 1.e4 c5 2.d3
D15 Chameleon Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 a6
D02 Chandler Gambit, QP 1.d4 d5 2.Nf3 c5 3.g3 cxd4 4.Bg2
A40 Charlick Gambit; Englund Gambit 1.d4 e5
C64 Charousek Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.c3 Bb6
C14 Chatard-Alekhine; Albin Attack, Fr 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4
B53 Chekhover Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Qxd4
B33 Chelyabinsk Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5
A00 Chenoboskian Variation, Durkin 1.Na3 g6 2.g4
A45 Chepukaitis Gambit 1.d4 Nf6 2.Bg5 c5 3.d5 Qb6 4.Nc3 Qxb2 5.Bd2 Qb6
B20 Chicago Defense, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 d6 5.Bc4 e6 6.Nf3 Nf6 7.O-O a6
C44 Chicago; Irish; Schulze-Muller Gambit 1.e4 e5 2.Nf3 Nc6 3.Nxe5 Nxe5 4.d4
C21 Chigorin Defense, Danish Gambit 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 Qe7
D07 Chigorin Defense, QGD; D07 1.d4 d5 2.c4 Nc6
C40 Chigorin Gambit, Damiano 1.e4 e5 2.Nf3 f6 3.Nxe5 Qe7 4.Nf3 d5
B08 Chigorin Line, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.Be2 O-O 6.O-O Nc6
A83 Chigorin Variation, Dutch 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.Bg5 c6
C00 Chigorin Variation, French 1.e4 e6 2.Qe2
C12 Chigorin Variation, French  1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.exf6
C42 Chigorin Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Be7 7.O-O Nc6 8.Re1
D46 Chigorin Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 Bd6
D02 Chigorin Variation, QP 1.d4 d5 2.Nf3 Nc6
C97 Chigorin Variation, Ruy Lopez; C97 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7  
D00 Chigorin; Ponziani; Veresov 1.d4 d5 2.Nc3
B07 Chinese Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Be2 Bg7 5.g4
C40 Chiodini Gambit 1.e4 e5 2.Nf3 Bc5 3.Nxe5 Nc6
C07 Chistiakov Defense, French 1.e4 e6 2.d4 d5 3.Nd2 c5 4.exd5 Qxd5
D20 Christensen Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e3 e5 4.Bc4 exd4 5.Qb3 Qe7 6.Nf3
C40 Clam Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.d3 Nc6 4.exf5
C20 Clam Variation; Leonardis Variation 1.e4 e5 2.d3
A43 Clarendon Court Variation, Benoni 1.d4 c5 2.d5 f5
C42 Classical Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4
C70 Classical Defense Deferred, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Bc5
D05 Classical Defense, Colle System; D05 1.d4 d5 2.Nf3 Nf6 3.e3 e6
C21 Classical Defense, Danish Gambit 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 Nf6
C33 Classical Defense, KGA; Lopez Variation 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5
C30 Classical Defense, KGD 1.e4 e5 2.f4 Bc5  
E48 Classical Defense, Nimzo-Indian; E48 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5
D26 Classical Defense, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5
D01 Classical Defense, Veresov 1.d4 d5 2.Nc3 Nf6 3.Bg5 e6 4.Nf3
B20 Classical Formation, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 a6 7.O-O Nf6
E05 Classical Line, Catalan; E05 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Nf3 Be7
D86 Classical Main Line, Grunfeld; D86 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4
B07 Classical System, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Be2
D34 Classical Tarrasch Gambit 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.dxc5 d4
A70 Classical Variation, Benoni; A70 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3
C23 Classical Variation, Bishop; Boi Variation 1.e4 e5 2.Bc4 Bc5  
B18 Classical Variation, Caro; B18 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Bf5
A84 Classical Variation, Dutch 1.d4 f5 2.c4 e6
A90 Classical Variation, Dutch  1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2
C48 Classical Variation, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bc5
C14 Classical Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7
C11 Classical Variation, French; C11 1.e4 e6 2.d4 d5 3.Nc3 Nf6
C53 Classical Variation, Italian; C53 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3
A01 Classical Variation, Larsen 1.b3 d5
D77 Classical Variation, Neo-Grunfeld; D77 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O
E32 Classical Variation, Nimzo-Indian; E32 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2
D67 Classical Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5 10.Bxe7 Qxe7 11.O-O Nxc3 12.Rxc3
E17 Classical Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O
C97 Classical Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.Nbd2
C45 Classical Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5
B56 Classical Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6
C64 Classical; Cordel Var, Ruy Lopez; C64 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5
A00 Clemenz Opening 1.h3
C66 Closed Bernstein Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bg5
C84 Closed Defense, Ruy Lopez; C84 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7
B01 Closed Scandavian 1.e4 d5 2.Nc3
C66 Closed Showalter Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Bxc6
A25 Closed System, Full Symmetry, King's English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6
A26 Closed System, King's English; A26 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3
E06 Closed Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2
E87 Closed Variation, KID; E87 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5
C66 Closed Wolf Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 exd4
B23 Closed; Chigorin Variation, Sicilian; B23 1.e4 c5 2.Nc3
B45 Cobra Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Ndb5 Bc5
A00 Coca-Cola Gambit, Grob 1.g4 g5 2.f4
C42 Cochrane Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nxf7
C37 Cochrane Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5  Qh4+ 6.Kf1 f3
D06 Cocquio Counter Gambit, QGD; Tan Gambit 1.d4 d5 2.c4 Nf6 3.cxd5 c6
D04 Colle System; D04 1.d4 d5 2.Nf3 Nf6 3.e3
B01 Collijn Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 e5 5.Nf3 Bg4
C58 Colman Variation, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Qf3 Rb8
A00 Cologne Gambit, Ware Opening 1.a4 b6 2.d4 d5 2.Nc3 Nd7
B00 Colorado Counter Accepted, Nimzovich Defense 1.e4 Nc6 2.Nf3 f5 3.exf5
B00 Colorado Defense, Nimzovich; Lean Variation 1.e4 Nc6 2.Nf3 f5
C52 Compromised Defense, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4 7.O-O dxc3
C21 Copenhagen Defense, Danish Gambit 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 Bb4+
C67 Cordel Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 Nd6 7.Bxc6+ bxc6 8.dxe5 Nf5
C64 Cordel Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.c3 f5
C51 Cordel Line, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Be7 6.d4 Na5
C40 Corkscrew Counter-Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Nf6 4.Bc4 fxe4 5.Nf7 Qe7 8.Nxh8 d5
A43 Cormorant Gambit, Benoni 1.d4 c5 2.dxc5 b6
B00 Corn Stalks 1.e4 a5
B28 Cortlever Gambit, Sicilian 1.e4 c5 2.Nf3 a6 3.d4 cxd4 4.Bc4
B53 Cortlever Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 Nf6 4.dxc5 Nxe4 5.cxd6
D07 Costa's Line 1.d4 d5 2.c4 Nc6 3.cxd5 Qxd5 4.e3 e5 5.Nc3 Bb4 6.Bd2 Bxc3 7.Bxc3 exd4 8.Ne2
C39 Cotter Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 h6 6.Nxf7
D28 Counter Fianchetto Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2 Nc6 8.dxc5
E60 Counterthrust Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d5
D71 Counterthrust Variation 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7
C42 Cozio (Lasker) Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Qe2
C33 Cozio Attack, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Qf3
C70 Cozio Defense Deferred, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nge7
C60 Cozio Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nge7
C33 Cozio Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 d6
C33 Cozio; Hanneken; Prussian; Lichtenhein 1.e4 e5 2.f4 exf4 3.Bc4 Nf6
C54 Cracow Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Kf1
A00 Krazy Kat 1.Nh3 e5 2.f3 d5 3.Nf2
A00 Creepy Crawly Formation 1.a3 e5 2.h3 d5
C21 Crocodile Variation, Center Game 1.e4 e5 2.d4 exd4 3.f4 Bc5 4.Nf3 Nc6 5.c3
C25 Cunningham Defense, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3 Be7
C35 Cunningham Gambit, KGA; C35 1.e4 e5 2.f4 exf4 3.Nf3 Be7
B07 Czech Defense 1.e4 d6 2.d4 Nf6 3.Nc3 c6
B08 Czech Defense, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.Be2 O-O 6.O-O c6
D17 Czech Defense; Open Slav Defense; D17 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5
A56 Czech Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e5 4.Nc3 d6 5.e4 Be7
A16 Czech Variation, English 1.c4 Nf6 2.Nc3 d5 3.cxd5 Nxd5 4.g3 g6 5.Bg2 Nb6
A46 Czech-Indian 1.d4 Nf6 2.Nf3 c6
A76 Czerniak Defesne, Benoni; A76 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.Nf3 Bg7 8.Be2 O-O 9.O-O Re8
B14 Czerniak Line, Caro-Kann 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nc3 Nc6 6.Bg5 Qa5
B77 Czerniak Variation, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 Nxd4 10.Bxe4
D22 D22 1.d4 d5 2.c4 dxc4 3.Nf3 a6 4.e3
D23 D23 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6
D25 D25 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3
D29 D29 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2 b5 8.Bb3 Bb7
D30 D30 1.d4 d5 2.c4 e6
D34 D34 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7
D35 D35 1.d4 d5 2.c4 e6 3.Nc3 Nf6
D41 D41 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.cxd5  
D42 D42 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.cxd5 Nxd5 6.e3 Nc6 7.Bd3
D43 D43 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6
D45 D45 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3
D46 D46 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3
D52 D52 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 c6 6.Nf3
D53 D53 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7
D55 D55 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3
D56 D56 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4
D57 D57 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 Ne4 8.Bxe7 Qxe7 9.cxd5
D62 D62 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Qc2 c5 8.cxd5
D63 D63 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1
D65 D65 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Qc2 a6 9.cxd5
D66 D66 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3
D68 D68 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5 10.Bxe7 Qxe7 11.O-O Nxc3 12.Rxc3 e5
D69 D69 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5 10.Bxe7 Qxe7 11.O-O Nxc3 12.Rxc3 e5 13.dxe5
D71 D71 1.d4 Nf6 2.c4 Nc6 3.g3 d5
D72 D72 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.cxd5 Nxd5 6.e4 Nb6
D73 D73 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3
D75 D75 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.cxd5 Nxd5 7.O-O c5
D76 D76 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.cxd5 Nxd5 7.O-O Nb6
D79 D79 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O c6 7.cxd5
D84 D84 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O 6.cxd5 Nxd5
D88 D88 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 c5 9.O-O Nc6 10.Be3 cxd4
D89 D89 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 c5 9.O-O Nc6 10.Be3 cxd4 11.cxd4 Bg4 12.f3 Na5 13.Bd3
D93 D93 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Bf4 O-O 6.e3
D95 D95 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.e3 O-O 6.Qb3
D97 D97 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4
D99 D99 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Bg4 8.Be3 Nfd7 9.Qb3
A00 Damhaug Gambit, Dunst 1.Nc3 d5 2.f4 e5
C40 Damiano Defense 1.e4 e5 2.Nf3 f6
C40 Damiano Gambit 1.e4 e5 2.Nf3 f6 3.Nxe5 fxe5 4.Qh5+ g6 5.Qxe5+ Qe7 6.Qxh8
C42 Damiano Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nxe4
C21 Danish Gambit 1.e4 e5 2.d4 exd4 3.c3
C21 Danish Gambit Accepted 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2
D70 Danube Gambit; Adorjan Gambit 1.d4 Nf6 2.c4 g6 3.d5 b5
D70 Danube; Donau Gambit 1.d4 Nf6 2.c4 g6 3.d5 b5 4.cxb5 a6 5.bxa6 c6
B12 De Bruycker Defense, Caro 1.e4 c6 2.d4 Na6
C55 De Riviere Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.c3
E67 Debrecen Defense, KID; E67 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nbd7 
E72 Deferred Fianchetto, KID; E72 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.g3
B50 Delayed Alapin, Sicilian 1.e4 c5 2.Nf3 d6 3.c3
C85 Delayed Exchange Ruy Lopez Deferred; C85 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Bxc6
C15 Delayed Exchange Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.exd5
D74 Delayed Exchange Variation, Neo-Grunfeld; D74 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.cxd5 Nxd5 7.O-O
E62 Delayed Fianchetto, KID; E62 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3
B81 Delayed Keres Attack, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be3 a6 7.g4
C41 Delmar Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Bc4 c6 5.c3
A00 Despres Opening 1.h4
C50 Deutz Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.O-O Nf6 5.d4
D26 Development Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O Nc6
E00 Devin Gambit, Catalan 1.d4 Nf6 2.c4 e6 3.g4
D00 Diemer Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Bf4
A40 Diemer Counterattack 1.d4 e5 2.d5 Bc5 3.e4 Qh4
D00 Diemer Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.fxe4
D10 Diemer Gambit, Slav 1.d4 d5 2.c4 c6 3.e4
B12 Diemer-Duhm Gambit, Caro 1.e4 c6 2.d4 d5 3.c4
C00 Diemer-Duhm Gambit, French 1.e4 e6 2.d4 d5 3.c4
D00 Diemer-Rosenberg Attack, BDG 1.d4 d5 2.e4 dxe4 3.Be3
C40 Diepstraten Countergambit, Latvian 1.e4 e5 2.Nf3 f5 3.c4
C82 Dilworth; Kleczynski Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5 10.Nbd2 O-O 11.Bc2
A57 Dlugy Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.f3
C33 Dodo Gambit, KGA 1.e4 e5 2.f4 exf4 3.Qg4
E94 Donner Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O c6
B51 Dorfman Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.Bb5+ Nc6 4.O-O Bd7 5.Qe2 g6 6.e5
E10 Dory (Doery) Defense 1.d4 Nf6 2.c4 e6 3.Nf3 Ne4
A46 Dory Defense 1.d4 Nf6 2.Nf3 Ne4
A30 Double Fianchetto Defense, English 1.c4 c5 2.Nf3 Nf6 3.g3 b6 4.Bg2 Bb7 5.O-O g6
A08 Double Fianchetto, KIA 1.Nf3 d5 2.g3 g6
E82 Double Fianchetto, KID; E82 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 b6
A38 Double Fianchetto, Symmetrical English 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 6.O-O O-O 7.b3
C56 Double Gambit Accepted, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4
A00 Double Grob 1.g4 g5
C37 Double Muzio Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6 7.e5 Qxe5 8.Bxf7+
C44 Double Pawn Sacrifice, Goering Gambit 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.c3 dxc3 5.Bc4
C49 Double Ruy Lopez Opening, 4 Knights; C49 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4
A20 Double Whammy, English 1.c4 e5 2.f4
B27 Double-Dutch Gambit, Sicilian 1.e4 c5 2.Nf3 f5 3.exf5 Nh6
A00 Dougherty Gambit, Dunst 1.Nc3 d5 2.e4 dxe4 3.f3
B09 Dragon Formation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 c5
B60 Dragon Variation, Richter-Rauzer Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 g6
B70 Dragon Variation, Sicilian; B70 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6
C44 Dresden Opening 1.e4 e5 2.Nf3 Nc6 3.c4
B12 Dreyev Defense, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.Nc3 Qb6
D00 Dries Counter-Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 c5
A20 Drill Variation, English 1.c4 e5 2.g3 h5
C33 Drunken King, KGA 1.e4 e5 2.f4 exf4 3.Kf2
A00 Drunken Knight Opening 1.Nh3
B20 Dubois Variation, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 d3 4.c4
A38 Duchamp Variation, Symmetrical English 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 6.O-O O-O 7.d3
A02 Dudweiller Gambit, Bird 1.f4 d5 2.g4
A00 Duesseldorf Gambit, Durkin 1.Nc3 c5 2.b4
C40 Duke of Courland Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Qg5 5.d4 Qxg2 6.Qh5 g6 7.Bf7 Kd8 9.Bg6 Qh1
A00 Dunst (Perrenet) Gambit 1.Nc3 d5 2.e4 dxe4 3.d3
A00 Dunst; Heinrichsen; Will Bull; Kotrc; Van Geet 1.Nc3
A40 Dunworth Variation, Modern Defense 1.e4 g6 2.d4 Bg7 3.c4 d5 4.exd5 c6 5.dxc6 Bxd4
C12 Duras Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Bd2 Bxc3 7.bxc3 Ne4 8.Qg4 Kf8 9.Bc1
D30 Duras Variation, QGD; Capablanca Variation 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Bg5 h6
C77 Duras Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d3 d6 6.c4
C65 Duras Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d3 d6 5.c4
A00 Durkin Gambit 1.Na3 e5 2.Nc4 Nc6 3.e4 f5
A00 Durkin's Opening; Sodium Attack 1.Na3
E10 Dus-Chotimursky Variation 1.d4 Nf6 2.c4 e6 3.Nf3 c5 4.d5 b5 5.Bg5
A80 Dutch Defense; A80 1.d4 f5
A81 Dutch Indian; Leningrad Variation, Dutch; A81 1.d4 f5 2.g3
D00 Dutch System, QP 1.d4 d5 2.Nc3 f5
A03 Dutch Variation, Bird; A03 1.f4 d5
A01 Dutch Variation, Larsen 1.b3 f5
D18 Dutch Variation, Slav; D18 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.e3
A04 Dutch Variation, Zukertort 1.Nf3 f5
D00 Duthilleuk Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6 6.Bd3 Nc6 7.Bg5 Be7 8.Ne4
A53 Duz-Khotimirsky Variation 1.d4 Nf6 2.c4 d6 3.Nc3 Nbd7 4.e3 e5 5.Bd3
E76 Dynamic Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Nf3 c5 7.d5
E10 Dzindzi-Indian Defense 1.d4 Nf6 2.c4 e6 3.Nf3 a6
E01 E01 1.d4 Nf6 2.c4 e6 3.g3 d5
E02 E02 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4
E03 E03 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Qa4+ Nbd7 6.Qxc4
E06 E06 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7
E07 E07 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7
E08 E08 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2
E09 E09 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2 c6 8.Nbd2
E13 E13 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb7 5.Bg5 h6 6.Bh4 Bb4
E18 E18 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.Nc3
E19 E19 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.Nc3 Ne4 8.Qc2
E20 E20 1.d4 Nf6 2.c4 e6 3.Nc3
E25 E25 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.f3 d5 7.cxd5
E27 E27 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 O-O
E28 E28 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 O-O 6.e3
E29 E29 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 O-O 6.e3 c5 7.Bd3 Nc6
E35 E35 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.cxd5 exd5
E36 E36 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.a3
E37 E37 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Ne4
E50 E50 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3
E54 E54 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O dxc4 8.Bxc4
E57 E57 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O Nc6 8.a3 dxc4 9.Bxc4 cxd4
E58 E58 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O Nc6 8.a3 Bxc3 9.bxc3
E59 E59 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O Nc6 8.a3 Bxc3 9.bxc3 dxc4 10.Bxc4
E61 E61 1.d4 Nf6 2.c4 g6 3.Nc3
E65 E65 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c5 7.O-O
E66 E66 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c5 7.O-O Nc6 8.d5
E68 E68 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nbd7 7.O-O e5 8.e4
E69 E69 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nbd7 7.O-O e5 8.e4 c6 9.h3
E73 E73 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2
E75 E75 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 c5 7.d5 c6
E77 E77 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Be2
E84 E84 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 Nc6 7.Nge2 a6 8.Qd2 Rb8
E86 E86 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.Nge2 c6
E88 E88 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 c6
E89 E89 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5 7.d5 c6 8.Nge2
E90 E90 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3
E92 E92 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5
E93 E93 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.d5 Nbd7
E94 E94 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O
E95 E95 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nbd7 8.Re1
E96 E96 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nbd7 8.Re1 c6 9.Bf1 a5
E98 E98 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Ne1
E00 East Indian Defense; E00 1.d4 Nf6 2.c4 e6
A40 Eastbourne Gambit 1.d4 b6 2.c4 Bb7 3.Bxb5
B25 Edge Variation, Sicilian Closed 1.e4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 6.f4 e5 7.Nh3 Nge7
A45 Edge Variation, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.Bh4
B12 Edinburgh Variation, Caro 1.e4 c6 2.d4 d5 3.Nd2 Qb6
C27 Eifel Gambit, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Bc5 4.Nge2 b5
C33 Eisenberg Variation, KGA 1.e4 e5 2.f4 exf4 3.Nh3
A00 Ekolu Variation 1.e3 e5 2.Nc3 d5 3.f4 exf4 4.Nf3
C81 Ekstrom Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Qe2 Be7 10.Rd1 O-O 11.c4
D44 Ekstrom Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.exf6 gxh4 10.Ne5
B00 El Columpio Defense, Nimzovich Defense 1.e4 Nc6 2.Nf3 Nf6 3.e5 Ng4
C40 Elephant Gambit; Queen Pawn Counter Gambit 1.e4 e5 2.Nf3 d5   
D00 Elbert Counter-Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 e5
C10 Ellis Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 e5
D00 Endgame Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e5 4.dxe5
D34 Endgame Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.Bg5 Be6
B80 English Attack, Scheveningen Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be3 a6 7.f3
A13 English Defense 1.c4 e6 2.d4 b6
A40 English Defense 1.d4 e6 2.c4 b6
E20 English Hybrid, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 c5 5.g3 O-O 6.Bg2 cxd4 7.Nxd4 d5 8.cxd5 Nxd5
A10 English Opening; A10 1.c4
A15 English Orangutan 1.c4 Nf6 2.b4
A20 English Queen 1.c4 e5 2.Qa4
A42 English Rat 1.d4 d6 2.c4 e5
A10 English Spike 1.c4 f5 2.g4
A01 English Variation, Larsen 1.b3 c5
C86 English Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Qe2 b5 7.Bb3 O-O 8.c3 d6 9.d4 Bg4
A40 Englund Gambit 1.d4 e5 2.dxe5 Nc6 3.Nf3 Qe7
A40 Englund Gambit Declined 1.d4 e5 2.d5
A40 Englund; Behting Gambit 1.d4 e5 2.dxe5 Nc6  
B00 Erben Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3 g6
C25 Erben Gambit, Vienna 1.e4 e5 2.Nc3 Nf6 3.g3 d5 4.exd5 c6
A22 Erbenheimer Gambit, English 1.c4 e5 2.Nc3 Nf6 3.Nf3 e4 4.Ng5 Ng4
D00 Euwe Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6  
C02 Euwe Variation, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Bd7
E21 Euwe Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 c5 5.d5 Ne4
E17 Euwe Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.b3
D00 Euwe Variation, Queen Pawn Game 1.d4 d5 2.Bg5 h6 3.Bh4 c6 4.Nf3 Qb6
A48 Euwe Variation, Torre Attack 1.d4 Nf6 2.Nf3 g6 3.Bg5 Bg7 4.Nbd2 c5
C51 Evans Gambit Accepted 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4
C51 Evans Gambit; C51 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4
B02 Everglades Defense, Alekhine 1.e4 Nf6 2.e5 Ng8 3.d4 f5
B13 Exchange Variation, Caro; B13 1.e4 c6 2.d4 d5 3.exd5
D07 Exchange Variation, Chigorin Defense 1.d4 d5 2.c4 Nc6 3.cxd5 Qxd5
E79 Exchange Variation, Four Pawns Attack, KID; E79 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Be2 c5 7.Nf3 cxd4 8.Nxd4 Nc6 9.Be3
C01 Exchange Variation, French 1.e4 e6 2.d4 d5 3.exd5 exd5
D85 Exchange Variation, Grunfeld; 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3
D85 Exchange Variation, Grunfeld; D85 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5
D71 Exchange Variation, Neo-Grunfeld 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.cxd5 Nxd5
C41 Exchange Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4
D35 Exchange Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5
B62 Exchange Variation, Richter-Rauzer Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Nxc6
C68 Exchange Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6
C63 Exchange Variation, Schliemann Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Bxc6
D10 Exchange Variation, Slav 1.d4 d5 2.c4 c6 3.cxd5
D13 Exchange Variation, Slav; D13 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.cxd5
D59 Exchange Variation, Tartakower Defense, QGD; D59 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 b6 8.cxd5 Nxd5
C02 Extended Bishop Swap, French 1.e4 e6 2.d4 d5 3.e5 Bd7
A51 Fajarowicz Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ne4
C31 Falkbeer Countergambit Accepted, KGD 1.e4 e5 2.f4 d5 3.exd5
C31 Falkbeer Counter-Gambit, KGD; C31 1.e4 e5 2.f4 d5  
C26 Falkbeer Variation, Vienna; C26 1.e4 e5 2.Nc3 Nf6
B12 Fantasy; Lilienfisch Variation, Caro 1.e4 c6 2.d4 d5 3.f3
E12 Farago Defense, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.a3 Ba6 5.Qc2 Bb7
D17 Fazekas Gambit, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Ne5 Na6 7.e4
A40 Felbecker Gambit 1.d4 e5 2.dxe5 Nc6 3.Nf3 Bc5
D00 Fianchetto Defense, QP 1.d4 d5 2.Nc3 g6 3.Nf3 Bg7
B20 Fianchetto Defense, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 g6
A48 Fianchetto Defense, Torre Attack 1.d4 Nf6 2.Nf3 g6 3.Bg5
B06 Fianchetto Gambit, Modern Defense 1.e4 g6 2.d4 f5
A29 Fianchetto Line, Four Knights English; A29 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.g3
A24 Fianchetto Lines, Two Knights Variation, English; A24 1.c4 e5 2.Nc3 Nf6 3.g3 g6
E15 Fianchetto System, QID; E15 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3
E16 Fianchetto Traditional, QID; E16 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7
D09 Fianchetto Variation, Albin Countergambit; D09 1.d4 d5 2.c4 e5 3.dxe5 d4 4.Nf3 Nc6 5.g3
A58 Fianchetto Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6 Bxa6 6.Nc3 g6 7.Nf3 d6 8.g3 Bg7 9.Bg2
A62 Fianchetto Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.g3 Bg7 8.Bg2
A86 Fianchetto Variation, Dutch; A86 1.d4 f5 2.c4 Nf6 3.g3
E60 Fianchetto Variation, KID 1.d4 Nf6 2.c4 g6 3.g3
D66 Fianchetto Variation, Orthodox Defense, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 b5
B58 Fianchetto Variation, Richter-Rauzer Sicilizn 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.g3
B80 Fianchetto Variation, Scheveningen Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g3
B24 Fianchetto Variation, Sicilian Closed; B24 1.e4 c5 2.Nc3 Nc6 3.g3
B70 Fianchetto Variation, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.g3
A34 Fianchetto Variation, Symmetrical English   1.c4 c5 2.Nc3 Nf6 3.g3
A36 Fianchetto Variation, Symmetrical English; A36 1.c4 c5 2.Nc3 Nc6 3.g3
E16 Fine Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Qc8 6.O-O c5 7.d5
C15 Fingerslip Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Bd2
B16 Finnish Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 h6
B86 Fischer Attack, Sozin Attack, Sicilian; B86 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4
C34 Fischer Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 d6
E44 Fischer Variation, Nimzo-Indian; E44 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 b6 5.Ne2
C89 Fischer Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6 12.g3
C66 Fishing Pole Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Ng4
B87 Flank Variation, Sicilian; B87 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4 a6 7.Bb3 b5
C45 Fleissig; Meitner Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.c3 Nge7 7.Nc2
E73 Flexible Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 h6
A28 Flexible Line, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.d3
A19 Floh-Mikenas-Carls Variation, English; A19 1.c4 Nf6 2.Nc3 e6 3.e4 c5
B05 Flohr Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Bg4 5.Be2 c6
B18 Flohr Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Bf5 5.Ng3 Bg6 6.Nh3
D80 Flohr Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Bd3 c6 7.O-O Bf5
D90 Flohr Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qa4+
B32 Flohr Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Qc7
D25 Flohr; Winawer Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 Be6
C92 Flohr; Zaitsev; Lenzerheide Var, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Bb7
A18 Flohr-Mikenas-Carls Variation, English; A18 1.c4 Nf6 2.Nc3 e6 3.e4
E77 Florentine Gambit, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Be2 c5 7.d5 e6 8.Nf3 exd5 9.e5
E78 Fluid Attack, KID; E78 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Be2 c5 7.Nf3
A87 Fluid Formation, Dutch 1.d4 f5 2.c4 Nf6 3.g3 g6 4.Bg2 Bg7 5.Nf3 O-O 6.O-O d6
D33 Folkestone; Swedish Var, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 c4
C40 Foltys Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4 fxe4 5.d3
C40 Foltys-Leonhardt Variation, Latvian Gambit 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4
B15 Forgacs Variation, Caro Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Nxf6+ exf6 6.Bc4
C10 Fort Knox Variation, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Bd7 5.Nf3 Bc6
C47 Four Knights Openng; C47 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6
A28 Four Knights Variation, English   1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.d4 exd4 5.Nxd4Bb4 6.Bg5 h6 7.Bh4 Bxc3+ 8.bxc3 Ne5
A28 Four Knights Variation, English; A28 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6
D28 Four Knights Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2 Nc6 8.Nc3
B45 Four Knights Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6
B33 Four Knights Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3
A34 Four Knights Variation, Symmetrical English 1.c4 c5 2.Nc3 Nf6 3.Nf3 Nf6
A68 Four Pawns Attack, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Nf3 O-O 
E76 Four Pawns Attack, KID; E76 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4
B03 Four Pawns Attack; Chase V 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.c4 Nb6 5.f4
A43 Franco-Benoni; Franco-Sicilian 1.d4 c5 2.d5 e6 3.e4
C01 Franco-Hiva Gambit I, French 1.e4 e6 2.d4 f5
C00 Franco-Hiva Gambit, French 1.e4 e6 2.d3 f5
A40 Franco-Indian Defense 1.d4 e6
B00 Franco-Nimzovich Variation 1.e4 Nc6 2.Nf3 e6
C00 Franco-Sicilian Defense 1.d4 e6 2.c4 c5  
A43 Franco-Sicilian Hybrid 1.d4 e6 2.c4 c5 3.d5 exd5 4.cxd5 d6 5.Nc3 g6 6.e4 Bg7 7.Nf3 Ne7
C27 Frankenstein-Dracula Var, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Qh5 Nd6 5.Bb3 Nc6 6.Nb5 g6 7.Qf3 f5 8.Qd5 Qe7
C60 Frankfort; Gunderam Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Qf6
C13 Frankfurt Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Ng8 6.Be3 b6
C45 Fraser Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Nf3
C51 Fraser Attack; Mortimer, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6 9.Nc3 Bg4 10.Qa4
C40 Fraser Defense, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Nc6
C33 Fraser Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Nc3 Bg7 6.g3 fxg3 7.Qf3
C25 Fraser-Minckwitz Variation, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.d4 Qh4+ 5.Ke2 b6
B90 Freak Attack, Siicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Rg1
B00 Fred; From Reversed 1.e4 f5
B27 Frederico Variation, Sicilian 1.e4 c5 2.Nf3 g6 3.d4 f5
C42 French Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d3
B00 French Connection, Nimzovich Defense 1.e4 Nc6 2.d4 e6
C00 French Defense; C00 1.e4 e6
B40 French Variation, Sicilian; B40 1.e4 c5 2.Nf3 e6
C02 Frenkel Gambit, French 1.e4 e6 2.d4 d5 3.e5 c5 4.b4
C10 Frere; Becker; Katilimov, Maric Var, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Qd5
C60 Fricke Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 d5 4.Nxe5 Qg5 5.O-O
B02 Fried Fox, Alekhine; Krejcik Gambit 1.e4 Nf6 2.Bc4 Nxe4 3.Bxf7+
C57 Fried Liver; Fegatello Attack, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6.Nxf7
C80 Friess Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Nxe5
D00 Fritz Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Bc4
A00 Fritz Gambit, Grob 1.g4 d5 2.Bg2 Bxg4 3.c4
C57 Fritz Variation, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nd4
C37 From Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qe7
A02 From's Gambit, Bird 1.f4 e5
A38 Full Symmetry Line, Symmetrical English; A38 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6
A58 Fully Accepted Variation, Benko Gambit; A58 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6
D27 Furman Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.dxc5 Bxc5
C70 Furman-Taimanov; Wing Var, Ruy; Norwegian Variation 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5 5.Bb3 Na5
C25 Fyfe Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.d4
C33 Gaga Gambit, KGA 1.e4 e5 2.f4 exf4 3.g3
C33 Gama Gambit, KGA 1.e4 e5 2.f4 exf4 3.g3 fxg3 4.Nf3
A00 Gambit 59; Buecker Gambit 1.g3 d5 2.Bg2 e5 3.b4
B28 Gambit Line, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.c3 d5 4.exd5 Nf6
B44 Gary Gambit, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nb5 d6 6.c4 Nf6 7.N1c3 a6 8.Na3 d5
B40 Gaw-Paw Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Qb6
A45 Gedult Attack 1.d4 Nf6 2.f3 d5 3.g4
A45 Gedult-Gunderam System 1.d4 Nf6 2.f3 d5 3.g4
E73 Geller Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 Nbd7
B28 Geller Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c4 Nc6 4.d4 cxd4 5.Nxd4 e5
C89 Geller Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6 12.d4 Bd6 13.Re1 Qh4 14.g3 Qh3
C45 Geller Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Nb3 Bb6 6.a4 a6 7.Nc3 Nf6
A33 Geller Variation, Symmetrical English 1.c4 c5 2.Nf3 Nf6 3.d4 cxd4 4.Nxd4 e6 5.Nc3 Nc6 6.g3 Qb6
D15 Geller Variation; Geller-Tolush Var, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.e4
B06 Geller's System, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nf3 d6 3.c3
A21 General Variation, King's English 1.c4 e5 2.Nc3 d6 3.Nf3
A83 General Variation, Staunton Gambit, Dutch; A83 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.Bg5
B02 Geschev Gambit, Alekhine 1.e4 Nf6 2.Nc3 d5 3.exd5 c6
C37 Ghulam Kassim; Koch Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4
C37 Ghulam-Kassim Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.d4 gxf3 6.Qxf3
C34 Gianutio Countergambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 f5
C33 Gianutio Counter-Gambit, KGA 1.e4 e5 2.f4 exf4 3.Bc4 f5
A45 Gibbins-Wiedehagen Gambit Accepted 1.d4 Nf6 2.g4 Nxg4
D80 Gibbon Gambit; Grunfeld Spike 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.g4
D00 Giertz-Peters Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e6 4.f3
B55 Ginsberg Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Bc4
B01 Gipslis Variation, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5 4.Nf3 Bg4
C25 Giraffe Attack, Vienna 1.e4 e5 2.Nc3 Bc5 3.Qg4
C53 Giuoco Pianissimo 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d3
C50 Giuoco Pianissimo 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d3  
C50 Giuoco Piano; Italian Opening 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5
A00 Gladbacher Gambit, Dunst 1.Nc3 e5 2.b3 d5 3.e4 dxe4 4.d3
A00 Glasscoe Gambit, Dunst 1.Nc3 f5 2.g4
C40 Glatz Gambit; Busch-Gass Gambit 1.e4 e5 2.Nf3 Bc5
C11 Gledhill Attack, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.Qg4
E94 Glek Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Na6
C69 Gligoric Variation, Ruy Lopez; C69 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.O-O f6
E92 Gligoric-Taimanov Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.Be3
B20 Gloria Variation, Sicilian 1.e4 c5 2.c4 d6 3.Nc3 Nc6 4.g3 h5
D21 Godes Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nd7
B32 Godiva Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Qb6
C51 Goering Attack, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6 9.Nc3 Na5 10.Bg5
C44 Goering Gambit Declined, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.c3 d5
C44 Goering Gambit, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.c3
C59 Goering Variation, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Be2 h6 9.Nf3 e4 10.Ne5
D70 Goglidze Attack 1.d4 Nf6 2.c4 g6 3.f3 d5
B10 Goldman Variation, Caro 1.e4 c6 2.Nc3 d5 3.Qf3
A16 Golombek Defense, English; Anti English 1.c4 Nf6 2.Nc3 d5
D03 Gossip Variation, QP 1.d4 d5 2.Nf3 Nf6 3.Bg5 Ne4
B23 Grand Prix Variation, Sicilian 1.e4 c5 2.Nc3 d6 3.f4
C70 Graz Variation, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5 5.Bb3 Bc5
A10 Great Snake, English 1.c4 g6  
C40 Greco Defense 1.e4 e5 2.Nf3 Qf6
C23 Greco Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.f4
C38 Greco Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.h4 h6 6.d4 d6
C54 Greco Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Nc3 Nxe4 8.O-O Nxc3
C33 Greco Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 Bc5
C40 Greco Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qe7
D20 Greco Variation, QGA 1.d4 d5 2.c4 dxc4 3.e4 b5
C38 Greco; Calabrian Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.h4 h6 6.d4 d6 7.hxg5 hxg5 8.Rxh8 Rxh8 9.Nc3
C37 Greco-Lolli; Wild Muzio Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Bxf7+
C39 Green; Kolisch Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 d6
C53 Grevo Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4
A00 Grigorian Variation, Polish 1.b4 Nc6
C12 Grigoriev Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.exf6 hxg5 7.fxg7 Rg8 8.h4 gxh4 9.Qg4
B72 Grigoriev Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.Qd2 O-O 9.O-O-O
C33 Grimm Attack, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Nc3 Bg7 6.d4 d6 7.e5
A53 Grinberg Gambit, Old Indian 1.d4 Nf6 2.c4 d6 3.Nc3 Bf5 4.e4
A00 Grob Gambit 1.g4 d5 2.Bg2 Bxg4
A00 Grob Gambit Declined 1.g4 d5 2.Bg2 c6
A00 Grob; Ahlhausen; Colibri; Fric; Genoa; Spike 1.g4
D00 Grosshans Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Bd7
A00 Gruenfeld Defense, Dunst 1.Nc3 d5 2.e4 dxe4 3.Nxe4 e5
B01 Gruenfeld Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bf5 6.Ne5 c6 7.g4
D01 Grunfeld Defense, Veresov 1.d4 d5 2.Nc3 Nf6 3.Bg5 Nbd7 4.Nf3 g6
D80 Grunfeld Defense; D80 1.d4 Nf6 2.c4 g6 3.Nc3 d5
D32 Grunfeld Gambit, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.dxc5 d4 7.Na4 b5
D83 Grunfeld Gambit; D83 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O
E11 Grunfeld Variation, Bogo-Indian 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ 4.Nbd2
D03 Grunfeld Variation, QP 1.d4 d5 2.Nf3 Nf6 3.Bg5 g6
B00 Guatemalan Defense 1.e4 b6 2.d4 Ba6
B01 Gubinsky-Melts Defense, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd6
B31 Gufeld Gambit, Sicilian 1.e4 c5 2.Nf3 Nc6 3.Bb5 g6 4.O-O Bg7 5.c3 e5 6.d4
C04 Guimard Variation, French 1.e4 e6 2.d4 d5 3.Nd2 Nc6 4.Ngf3 Nf6 5.e5 Nfd7
D00 Gunderam Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.g4 Bg6 6.h4
D00 Gunderam Defense, BDG; Rook Pawn Defense 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 h5
C40 Gunderam Gambit 1.e4 e5 2.Nf3 c6
C40 Gunderam Gambit 1.e4 e5 2.Nf3 Qe7 3.Bc4 f5
D31 Gunderam Gambit, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.e4 dxe4 5.f3
D00 Gunderam; Tartakower Var, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Bf5
D21 Gunsberg Defense, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 c5
C45 Gunsberg Defense, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.c3 Nge7 7.Bb5 Nd8
D20 Gunsberg Defense; Prianishenmo Gambit, QGA 1.d4 d5 2.c4 dxc4 3.Nc3 c5 4.d5 Nf6 5.Nc3 e6 6.e4 exd5 7.e5
C47 Gunsberg Variation, Four Kngiths 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3
B06 Gurgenidze Defense, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nc3 c6 4.f4 d5 5.e5 h5
B15 Gurgenidze System, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 g6
B15 Gurgenidze Variation, Caro 1.e4 c6 2.d4 d5 3.Nc3 b5
B15 Gurgenidze Variation, Caro 1.e4 c6 2.d4 d5 3.Nc3 g6 4.e5 Bg7 5.f4 h5
B31 Gurgenidze Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.Bb5 g6 4.O-O Bg7 5.Re1 e5 6.b4
B36 Gurgenidze Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.c4 Nf6 6.Nc3 Nxd4 7.Qxd4 d6
D06 Gusev Countergambit, QGD 1.d4 d5 2.c4 c5 3.cxd5 Nf6
C03 Haberditz Variation, French 1.e4 e6 2.d4 d5 3.Nd2 f5
D22 Haberditz Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 a6 4.e3 b5
D06 Haberditz Variation, QGD 1.d4 d5 2.c4 c5 3.cxd5 Nf6 4.e4 Nxe4 5.dxc5 Qa5+
A43 Habichd; Hawk Variation, Benoni 1.d4 c5 2.d5 Nf6 3.Nf3 c4
B20 Halasz Gambit, Sicilian 1.e4 c5 2.d4 cxd4 3.f4
C40 Halasz-Jacobsen Gambit 1.e4 e5 2.Nf3 d5 3.exd5 Bd6
C21 Halasz-McDonnell Gambit 1.e4 e5 2.d4 exd4 3.f4
C50 Half Giuoco Piano; Semi-Italian Opening 1.e4 e5 2.Nf3 Nc6 3.Bc4 d6
A10 Halibut Gambit, English 1.c4 b5
C22 Hall Variation, Center 1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qc4
C46 Halloween Gambit, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Nxe5
B00 Hammer Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 f6
A00 Hammerschlag; Pork Chop Opening 1.f3 e5 2.Kf2
C25 Hamppe Meitner, Vienna 1.e4 e5 2.Nf3 Bc5 3.Na4
C25 Hamppe-Allgaier Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3 g5 5.h4 g4 6.Ng5
C25 Hamppe-Allgaier-Thorold Gambit 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3 g5 5.h4 g4 6.Ng5 h6 7.Nxf7 Kxf7 8.d4
C25 Hamppe-Mietner Variation, Vienna 1.e4 e5 2.Nc3 Bc5 3.Na4
C25 Hamppe-Muzio Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3 g5 5.Bc4 g4 6.O-O
A00 Hanham; Hayward 1.c3 e5 2.Qc2
C41 Hanham; Lord Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7
D00 Hans Mullers; Vienna V 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5
C38 Hanstein Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.O-O
C60 Harding Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 d5 4.Nxe5 Qg5 5.Nxc6
C80 Harksen Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.c4
D37 Harrwitz Attack, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 Be7 5.Bf4
D35 Harrwitz; Rubinstein Var, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bf4
A40 Hartlaub Gambit Accepted 1.d4 e6 2.c4 b6 3.Nc3 Bb7 4.e4 f5 5.exf5 Nf6
A40 Hartlaub Gambit Declined 1.d4 e6 2.c4 b6 3.Nc3 Bb7 4.e4 f5 5.d5
A40 Hartlaub Gambit, English 1.c4 b6 2.d4 Bb7 3.Nc3 e6 4.e4 f5 5.exf5 Nf6
A62 Hastings Defense, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.g3 Bg7 8.Bg2 O-O 9.O-O Nbd7
D30 Hastings Variation, QGD 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Bg5 h6 5.Bxf6 Qxf6 6.Nc3 c6 7.Qb3
A43 Hawk Variation, Benoni 1.d4 c5 2.d5 Nf6 3.Nf3 e4
C30 Heath Variation, KGD; Rotlewi Countergambit 1.e4 e5 2.f4 Bc5 3.Nf3 d6 4.b4
B12 Hector Gambit, Caro 1.e4 c6 2.Nc3 d5 3.Nf3 dxe4 4.Ng5
A00 Hector Gambit, Dunst 1.Nc3 d5 2.e4 dxe4 3.Bc4
C66 Hedgehog Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7
E12 Hedgehog Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb7 5.a3 g6
B41 Hedgehog Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.c4 g6
A30 Hedgehog Variation, Symmetrical English 1.c4 c5 2.Nf3 Nf6 3.g3 b6 4.Bg2 Bb7 5.O-O e6 6.Nc3 Be7
A17 Hegehog System, Anglo-Indian English; A17 1.c4 Nf6 2.Nc3 e6
C51 Hein Countergambit, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 d5
B00 Hekili-Loa Gambit, Owen Defense 1.e4 b6 2.d4 c5 3.dxc5 Nc6
C11 Henneberger Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Be3
D63 Henneberger; Swiss Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 a6
D53 Heral Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.Bxf6
B00 Herford Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 Qh4
A45 Hergert Gambit #1, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.Bh4 d5 4.f3 Nf6 5.Nc3 Bf5 6.e4
A45 Hergert Gambit #2, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.Bh4 c6 4.Nd2 Qa5 5.c3 Nxd2 6.Qxd2 d5 7.e4
A45 Hergert Gambit, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.h4 Nxg5 4.hxg5 e5
A04 Herrstrom Gambit, Reti 1.Nf3 g5
C37 Herzfeld; Portuguese; Vienna, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5  Qh4+ 6.Kf1 Nc6
A80 Hevendehl Gambit, Dutch 1.d4 f5 2.g4 e5
A10 Hickmann Gambit, English 1.c4 f5 2.e4
A10 Hickmann Gambit, English 1.c4 f5 2.e4 fxe4 3.d3
B10 Hillbilly Attack, Caro-Kann 1.e4 c6 2.Bc4
C31 Hinrichsen Gambit, KGD 1.e4 e5 2.f4 d5 3.d4
B00 Hippopotamus Defense 1.e4 Nh6 2.d4 g6
A02 Hobbs Gambit, Bird 1.f4 g5
A02 Hobbs-Zilbermints Gambit, Bird 1.f4 h6 2.Nf3 g5
C01 Hoffman Gambit 1.e4 e6 2.d4 d5 3.Qe2 e5 4.f4 exf4
C37 Holloway Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Nc6
A80 Hopton Attack, Dutch 1.d4 f5 2.Bg5
B00 Hornung Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Be3
C39 Horny Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Qxg4 Nf6 8.Qxf4
A03 Horsefly Defense, Bird 1.f4 Nh6
A50 Horsefly Gambit 1.d4 Nf6 2.c4 Nc6 3.d5 Ne5 4.f4
C45 Horwitz Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Nb5
A40 Horwitz Defense 1.d4 e6
C23 Horwitz Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.Nc3 b5
C81 Howell Attack, Ruy Lopez; C81 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Qe2
A56 Hromadka Defense; Loose Gambit: A56 1.d4 Nf6 2.c4 c5
A56 Hromadka System, Benoni 1.d4 Nf6 2.c4 c5 3.d5 d6
C24 Hromadka Variation, Bishop 1.e4 e5 2.Bc4 Nf6 3.d3 Nc6 4.Nc3 Bb4 5.Ne2
D00 Hubsch Gambit 1.d4 d5 2.Nc3 Nf6 3.e4 Nxe4
E50 Huebner Deferred, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 c5
E41 Huebner Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Bd3 Nc6 6.Nf3 Bxc3
E41 Huebner Variation, Nimzo-Indian; E41 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5
A45 Huebsch Gambit 1.d4 Nf6 2.Nc3 d5 3.e4 Nxe4
A00 Hulsemann Gambit, Dunst 1.Nc3 e5 2.e3 d5 3.Qh5 Be6
A25 Hungarian Attack, English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 4.Rb1
D92 Hungarian Attack, Grunfeld; D92 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Bf4 
C50 Hungarian Defense 1.e4 e5 2.Nf3 Nc6 3.Bc4 Be7
E00 Hungarian Gambit, Catalan 1.d4 Nf6 2.c4 e6 3.g3 e5
D97 Hungarian Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 a6
B02 Hunt Gambit, Alekhine; Two Pawn Attack 1.e4 Nf6 2.e5 Nd5 3.c4
B03 Hunt Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.c4 Nb6 5.c5
A00 Hurst Attack, Grob 1.g4 e5 2.Bg2 d5 3.c4
B27 Hyperaccelerated Dragon, Sicilian 1.e4 c5 2.Nf3 g6
B27 Hyperaccelerated Pterodactyl, Sic 1.e4 c5 2.Nf3 g6 3.d4 Bg7
D70 Iago Defense 1.d4 Nf6 2.c4 Nc6
C17 Icelandic Defense, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.Bd2 Ne7 6.f4
B01 Icelandic-Palme Gambit, CC 1.e4 d5 2.exd5 Nf6 3.c4 e6
A81 Ilyin-Genevsky Variation, Dutch 1.d4 f5 2.g3 Nf6 3.Bg2 e6 4.Nf3 Be7 5.O-O O-O 6.c4 d6
A97 Ilyin-Zhenevsky Variation, Dutch; A97 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Be7 5.Nf3 O-O 6.O-O d6 7.Nc3 Qe8
A06 Improved Lisitsin G, Reti 1.Nf3 f5 2.d3
C66 Improved Steinitz Defense, Ruy Lopez; C66 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6
A45 Indian Defense; A45 1.d4 Nf6
C20 Indian Opening 1.e4 e5 2.d3
A01 Indian Variation, Larsen 1.b3 Nf6   
C45 Intermezzo Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Nxc6 Qf6
C44 Inverted Hanham Opening 1.e4 e5 2.Nf3 Nc6 3.Be2 Nf6 4.d3 d5 5.Nbd2
A00 Irish Attack; Polish Attack 1.Nc3 e5 2.f4
D00 Irish Gambit, QP 1.d4 d5 2.Nc3 c5
C50 Italian Four Knights Variation 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d3 Nf6 5.Nc3  
C50 Italian Game; C50 1.e4 e5 2.Nf3 Nc6 3.Bc4
C46 Italian Variation, Four Knights   1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bc4
C50 Italian Variation, Four Knights Game 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Nc3 Nf6
C82 Italian Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5
B17 Ivanchuk Defense, Caro Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ndf6
B63 Ivanov Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 Qb6
C41 Jaenisch Counter-Attack, Philidor; Nimzovich Variation 1.e4 e5 2.Nf3 d6 3.d4 Nf6
C44 Jaenisch Counterattack, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 Nf6
C63 Jaenisch Gambit Accepted, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.exf5
C70 Jaenisch Gambit Deferred, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 f5 5.exf5
C33 Jaenisch Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 Nf6
C33 Jaenisch Variation, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 Qf6
C42 Jaenisch Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Be7 7.O-O Nc6 8.c4
C77 Jaffe Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.c3
B41 Jaffe Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Bb4 6.Bd3 e5
C40 Jalalabad Defense 1.e4 e5 2.Nf3 c5
B27 Jalalabad Variation, Sicilian 1.e4 c5 2.Nf3 e5
C49 Janowski Variation, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 Bxc3 7.bxc3 d6 8.Re1
C12 Janowski Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Be3
A53 Janowski Variation, Old Indian 1.d4 Nf6 2.c4 d6 3.Nc3 Bf5
D64 Janowski Variation, Orthodox Defense, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Bd3 dxc4 9.Bxc4 Nd5 10.h4
D31 Janowski Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 a6
D07 Janowski Variation, QGD 1.d4 d5 2.c4 Nc6 3.Nc3 dxc4 4.Nf3
A80 Janzen-Korchnoi Gambit, Dutch 1.d4 f5 2.h3 Nf6 3.g4
C50 Jerome Gambit; Kentucky Opening 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 
B02 John Tracy Gambit, Alekhine 1.e4 Nf6 2.Nf3
C56 Jordansky Attack, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4 6.Re1 d5 7.Bxd5 Qxd5 8.Nc3 Qa5 9.Ne4 Be6 10.Bg5
B01 Kadas Gambit, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 c6 4.dxc6 e5
A00 Kadas Opening 1.h4
A20 Kahiko-Hula Gambit, English 1.c4 e5 2.e3 Nf6 4.f4 exf4 4.Nf3
B32 Kalashnikov Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 e5 5.Nb5 d6
D00 Kampars Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.g4 Bg6 6.g5 Nd5 7.fxe4
B20 Kan Formation, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 a6
B28 Kan Line, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d4 cxd4 4.Nxd4 e6
C15 Kan Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Ne2 dxe4 5.a3 Bxc3+ 6.Nxc3 Nc6
A22 Kapengut; Smyslov; Modern V, English 1.c4 e5 2.Nc3 Nf6 3.g3 Bb4
C42 Karklins-Martinovsky Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nd3
A00 Karniewski; Tubingen Variation, Polish 1.b4 Nh6
C80 Karpov Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.Nbd2 Nc5 10.c3 d4
B04 Karpov Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 g6 5.c4 Nb6 6.h3 Bg7 8.Be2
B17 Karpov Variation, Caro-Kann; B17 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7
B17 Kasparov Attack, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Nf3 Ngf6 6.Ng3
E12 Kasparov Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3
E12 Kasparov-Petrosian Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb7 5.a3
B27 Katalimov Variation, Sicilian 1.e4 c5 2.Nf3 b6
C42 Kaufmann Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.c4
C65 Kaufmann Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d3 Bc5 5.Be3
C29 Kaufmann Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.Nf3 Bg4 6.Qe2
D00 Kaulich Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 c5
E62 Kavalek Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c6 7.O-O Qa5
E91 Kazakh Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Na6
C87 Kecskemet; Timbuktu Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 d6 7.c3 O-O 8.d4 Bd7 9.Nbd2 Be8
A00 Keene Defense, Grob 1.g4 d5 2.h3 e5
A00 Keene Defense, Grob 1.g4 d5 2.h3 e5 3.Bg2 c6
C30 Keene Defense, KGD 1.e4 e5 2.f4 Qh4+ 3.g3 Qe7
A28 Keene; Stean Variation, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.e3 Bb4 5.Qc2 O-O 6.Nd5 Re8 7.Qf5
C24 Keidansky Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3 Nxe4 5.Qxd4
E60 Kemeri Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d5 5.cxd5 Nxd5 6.Nf3 O-O 7.O-O c5
D85 Kemeri Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.g3
D80 Kemeri Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.g3
D70 Kemeri; Neo-Grunfeld  1.d4 Nf6 2.c4 g6 3.g3 d5
B00 Kennedy Variation, Nimzovich 1.e4 Nc6 2.d4 e5
A00 Keoni-Hiva Gambit 1.e3 d5 2.Nc3 Nf6 3.a3 e5 4.f4 exf4 5.Nf3
B00 Keres Attack, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 Nxe5 4.Nc3
A21 Keres Defense, English 1.c4 e5 2.Nc3 d6 3.g3 c6
A14 Keres Defense, English 1.c4 e6 2.Nf3 d5 3.g3 Nf6 4.Bg2 Be7 5.O-O c5 6.cxd5 Nxd5 7.Nc3 Nc6
A40 Keres Defense, Indian; Kangaroo Defense 1.d4 e6 2.c4 Bb4+
E33 Keres Defense, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 O-O 5.a3 Bxc3+ 6.Qxc3 b6
C92 Keres Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nd7
A00 Keres Gambit, Grob 1.g4 d5 2.Bg2 c6 3.c4 dxc4 4.c3
B04 Keres Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 g6 5.Bc4 Nb6 6.Bb3 Bg7 7.a4
A23 Keres Variation, English; A23 1.c4 e5 2.Nc3 Nf6 3.g3 c6
D98 Keres Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Bg4 8.Be2 Nfd7 9.Be2 Nb6 10.Qd3 Nc6 11.O-O-O Qc8
C32 Keres Variation, KGD 1.e4 e5 2.f4 d5 3.exd5 e4 4.d3 Nf6 5.Nd2
A07 Keres Variation, KIA 1.Nf3 d5 2.g3 Bg4 3.Bg2 Nd7
E93 Keres Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.d5 Nbd7 8.Bg5 h6 9.Bh4 g5 10.Bg3 Nh5 11.h4
E25 Keres Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.f3 d5 7.cxd5 Nxd5 8.dxc5
E40 Keres Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 d5 5.a3 Bxc3+ 6.bxc3 c5 7.cxd5 exd5 8.Bd3 O-O 9.Ne2 b6
E53 Keres Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O b6
C71 Keres Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c4
C92 Keres Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 a5
C96 Keres Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Nd7
C68 Keres Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 bxc6 5.Nc3
C33 Keres, Mason, Parnu, Requena 1.e4 e5 2.f4 exf4 3.Nc3
B20 Keres; Billium Attack, Sicilian; Chameleon 1.e4 c5 2.Ne2
C81 Keres; Estonian; Howell; Moscow Var 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6
B81 Keres; Panov Variation, Sicilian; B81 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.g4
A34 Keres-Parma System, English 1.c4 c5 2.Nc3 Nf6 3.Nf3 e6 4.g3 Nc6
A18 Kevitz Defense, English 1.c4 Nf6 2.Nc3 e6 3.e4 Nc6
C89 Kevitz Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6 12.Bxd5 cxd5 13.d4 Bd6 14.Re3
C23 Khan Gambit, Bishop 1.e4 e5 2.Bc4 d5
C42 Kholmov Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nxe4 4.Qe2 Qe7
B07 Kholmov System, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bc4
C92 Kholmov Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Be6
C20 Kiddie Countergambit 1.e4 e5 2.Qh5 Nf6
B01 Kiel Variation, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5 4.c4 Nb4
C33 Kieseritzky Gambit, Bishop's Gambit, KGA 1.e4 e5 2.f4 exf4 3.Bc4 b5
C39 Kieseritzky Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5
B28 Kieseritzky System, Sicilian 1.e4 c5 2.Nf3 a6 3.b3
C58 Kieseritzky; Morphy Var, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.d3
B20 King David's Opening 1.e4 c5 2.Ke2
C20 King Pawn Game; C20 1.e4 e5
A65 King Pawn lines, Benoni; A65 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4
A59 King Walk Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6 Bxa6 6.Nc3 d6 7.e4 Bxf1 8.Kxf1 g6 9.g3 Bg7 10.Kg2 O-O
C00 King"s Indian Attack 1.e4 e6 2.d3  
A80 Kingfisher Gambit, Dutch 1.d4 f5 2.Nc3 d5 3.e4
C68 King's Bishop Variation, Ruy Lopez Exchange 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 5.O-O Bd6
A20 King's English; A20 1.c4 e5  
C33 King's Gambit Accepted; C33 1.e4 e5 2.f4 exf4
C20 King's Gambit Reversed  1.e4 e5 2.d3 f5
C23 King's Gambit Reversed, Bishop 1.e4 e5 2.Bc4 f5
C30 King's Gambit; C30 1.e4 e5 2.f4
C20 King's Head 1.e4 e5 2.f3  
C20 King's Head Opening 1.e4 e5 2.f3 Nf6 3.Nc3
A00 King's Head Opening 1.f3 e5 2.e4
A05 King's Indian Attack; Reti; Zukertort; A05 1.Nf3 Nf6
D70 King's Indian Defense; West Indian Defense; D70 1.d4 Nf6 2.c4 g6
E60 King's Indian Defense; West Indian Defense; E60 1.d4 Nf6 2.c4 g6
A56 King's Indian System, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e5 4.Nc3 d6 5.e4 g6
A48 King's Indian Variation 1.d4 Nf6 2.Nf3 g6 3.e3 Bg7 4.Bd3 d6
C34 King's Knight Gambit, KGA; C34 1.e4 e5 2.f4 exf4 3.Nf3
C40 King's Knight Opening; C40 1.e4 e5 2.Nf3
A13 King's Knight Variation, English 1.c4 e6 2.Nf3 d5
A15 King's Knight Variation, English 1.c4 Nf6 2.Nf3
E60 King's Knight Variation, KID 1.d4 Nf6 2.c4 g6 3.Nf3
A43 Kingside move order, Benoni 1.d4 c5 2.d5 Nf6 3.Nf3
C24 Kitchner Folly, Bishop 1.e4 e5 2.Bc4 Nf6 3.d3 Be7 4.Nf3 O-O
C41 Klein Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.Bc4
C37 Kling & Horwitz Counter-Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O Qe7
D00 Kloss Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Bc4 Bg7 7.O-O O-O 8.Kh1
C57 Kloss Gambit, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nb4
A00 Kluever Gambit, Dunst 1.Nf3 f5 2.e4 fxe4 3.d3
B02 Kmoch Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.Bc4 Nb6 4.Bb3 c5 5.d3
E20 Kmoch Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.f3
D51 Knight Defense, QGD; D51 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7
B15 Knight Variation, Caro 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6
C00 Knight Variation, French 1.e4 e6 2.Nf3
C25 Knight Variation, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3
A46 Knights Variation, Indian Game; A46 1.d4 Nf6 2.Nf3
C80 Knoore Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.Nc3
B41 Koch Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Bb4 6.e5
C37 Koch; Ghulam Kassim Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.d4
C15 Kondratiyev Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Bd3 c5 5.exd5 Qxd5 6.Bd2
C64 Konikowski Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.c3 d5
C44 Konstantinopolsky Opening 1.e4 e5 2.Nf3 Nc6 3.g3
A00 Koola-Koola 1.h4 a5
C74 Kopaiev Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 f5 6.exf5 Bxf5 7.O-O
B50 Kopec System, Sicilian 1.e4 c5 2.Nf3 d6 3.Bd3
E97 Korchnoi Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Bd2
B23 Korchnoi Defense, Sicilian 1.e4 c5 2.Nc3 e6 3.g3 d5
D20 Korchnoi Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e3 e5 4.Bc4 exd4 5.Qb3 Qe7 6.Kf1
A28 Korchnoi Line, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.a3
E21 Korchnoi Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 c5 5.d5
A80 Korchnoi's Variation, Dutch 1.d4 f5 2.h3
A16 Korchnoi's Variation, English 1.c4 Nf6 2.Nc3 d5 3.cxd5 Nxd5 4.Nf3 g6 5.g3 Bg7 6.Bg2 e5
A52 Kornl Richter Gambit, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Bf4 Nc6 5.Nf3 Bb4+ 6.Nc3 Bxc3+
C63 Kostic Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 fxe4 5.Nxe4 Be7
C63 Kostic Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 Nf6 5.exf5 Bc5
C37 Kotov Gambit 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.d4 gxf3 6.Bxf4
B50 Kotov Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.g3 b5
A40 Kotov Variation, Modern 1.d4 g6 2.c4 Bg7 3.Nc3 d6 4.e4 Nc6
A40 Kotov-Robatsch Defense 1.d4 g6 2.c4 Bg7
E98 Kozul Gambit, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.Ne1 Nd7 10.Be3 f5
E70 Kramer Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.Nge2
E17 Kramnik Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.Re1
B40 Kramnik Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.c4
D85 Kramnik's Line, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Nf3 c5 8.h3
A21 Kramnik-Shirov Variation, English 1.c4 e5 2.Nc3 Bb4
D17 Krause Attack, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Ne5
C47 Krause Gambit, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 Bb4 5.Nxe5
A84 Krause Variation, Dutch 1.d4 f5 2.c4 Nf6 3.Nc3 d6 4.Nf3 Nc6
C41 Krause Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Bc4 c6 5.O-O
A45 Kraus-Muhlherr Counter Gambit 1.d4 Nf6 2.f3 d5 3.e4 e5 4.dxe5 Nxe4
C23 Kreijcik Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.f3 Bc5 4.Ne2 Nc6 5.b4
C20 Krejcik Gambit 1.e4 e5 2.f3 Nf6 3.Bc4 Bc5 4.Ne2 Nc6 5.b4
B02 Krejcik Variation, Alekhine 1.e4 Nf6 2.Bc4  
C15 Kunin Double Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Bd2 dxe4 5.Qg4 Qxd4
C22 Kupreichik Variation, Center 1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qe3 Nf6 5.Nc3 Bb4 6.Bd2 O-O 7.O-O-O Re8 8.Bc4
B56 Kupreichik Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Bd7
A13 Kurajica Defense, English 1.c4 e6 2.Nf3 d5 3.g3 c6
B09 Kurajica Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 O-O 6.Be3
C57 Kurkin Gambit, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 b5 6.Bf1 h6 7.Nxf7
B40 Kveinis Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Qb6
C40 Labourdonnais Gambit 1.e4 e5 2.Nf3 Qf6 3.Bc4 Qg6 4.O-O
C53 Labourdonnais Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 d6 5.d4 exd4 6.cxd4 Bb6
C23 Labourdonnais-Denker Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.b4 Bxb4 4.c3
D00 Lamb Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Nc6
C21 Lanc-Arnold Gambit, Center 1.e4 e5 2.d4 exd4 3.Nf3 Bc5 4.c3
B12 Landau Gambit, Caro-Kann 1.e4 c6 2.d4 d5 3.Bd3 Nf6 4.e5 Nfd7 6.e6
D12 Landau Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5 5.cxd5 cxd5 6.Qb3 Qc8 7.Bd2 e6 8.Na3
D00 Lange Gambit; Alfred Lange Gambit; Simple Variation 1.d4 d5 2.e4 dxe4 3.Nc3 e5 4.Nxe4
C51 Lange Variation, Evans Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bb6 5.b5 Na5 6.Nxe5 Nh6
D00 Langeheinecke Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 e3
A02 Langheld Gambit, Bird 1.f4 e5 2.fxe5 d6 3.exd6 Nf6
C41 Larobok Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.Nc3 Nbd7
A00 Laroche Gambit, Dunst 1.Nc3 b5
E62 Larsen Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c6 7.O-O Bf5
B20 Larsen Defense, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 a6 7.O-O Qc7 8.Qe2 Bd6
B04 Larsen Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 dxe5
D86 Larsen Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 Qd7
D86 Larsen Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 Qd7 9.O-O b6
E90 Larsen Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be3
C41 Larsen Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4 4.Nxd4 g6
D47 Larsen Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 Bb7 9.e4 b4 10.Na4 c5
D25 Larsen; Janowski; Modern Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 Bg4
A01 Larsen; Queen's Fianchetto; Nimzo-Larsen Attack A01 1.b3
B21 Larsen-Santasiere (McDonnell Attack) Variation, Sicilian; B21 1.e4 c5 2.f4
C20 Lasa Gambit 1.e4 e5 2.c3 f5
C52 Lasker Defense, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 d6 7.O-O Bb6
D53 Lasker Defense, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 Ne4
A02 Lasker Gambit, Bird 1.f4 e5 2.fxe5 f6
A00 Lasker Simul Special 1.g3 h5
D08 Lasker Trap, QGD 1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3 Bb4+ 5.Bd2 dxe3
B02 Lasker Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.c4 Nb6 4.c5
A02 Lasker Variation, Bird 1.f4 e5 2.fxe5 d6 3.exd6 Bxd6 4.Nf3 g5
B01 Lasker Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3
A83 Lasker Variation, Dutch 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.Bg5 g6 5.f3
C12 Lasker Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Bd2 Bxc3
C42 Lasker Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Qe2
D56 Lasker Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 Ne4 8.Bxe7 Qxe7
B33 Lasker-Pelikan Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5
C40 Latvian Gambit Accepted 1.e4 e5 2.Nf3 f5 3.exf5
C40 Latvian; Greco Counter-Gambit 1.e4 e5 2.Nf3 f5
D06 Lazard Gambit, Chigorin Defense 1.d4 d5 2.c4 Nc6 3.Nf3 e5
A45 Lazard Gambit; Maddigan Gambit 1.d4 Nf6 2.Nd2 e5
B53 Lazy Knight Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 Nd7
D70 Leko Gambit 1.d4 Nf6 2.c4 g6 3.f3 e5
A05 Lemberg Gambit, Zukertort 1.Nf3 Nf6 2.e4
D00 Lemberger Counter-Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e5
B00 Lemming Defense 1.e4 Na6
A86 Leningrad Variation, Dutch 1.d4 f5 2.c4 Nf6 3.g3 g6
C04 Leningrad Variation, French 1.e4 e6 2.d4 d5 3.Nd2 Nc6 4.Ngf3 Nf6 5.e5 Nfd7 5.f4 c5 6.c3 Nc6 7.Ndf3 cxd4 8.cxd4
E30 Leningrad Variation, Nimzo-Indian; E30 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Bg5
C33 Leonardo (Stamma) Gambit, KGA 1.e4 e5 2.f4 exf4 3.h4
B01 Leonhardt (Rosen) Gambit, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.b4
C47 Leonhardt Defense, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 Bb4 5.Nxe5 Qe7
C52 Leonhardt Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 b5
C40 Leonhardt Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.Nc4 fxe4 5.Nc3
C44 Leonhardt Variation, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Qa4 Nf6
C90 Leonhardt Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 Na5 9.Bc2 c5 10.d4 Qc7 11.h3 Nc6 12.d5 Nd8 13.Nbd2 g5
B88 Leonhardt Variation, Sicilian; B88 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4 Nc6
C33 Lesser Bishop; Tartakower 1.e4 e5 2.f4 exf4 3.Be2
E62 Lesser Simagin (Spassky) Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nc6 7.O-O Bf5
A04 Lessing Defense; Black Mustang Defense 1.Nf3 Nc6
D97 Levenfish Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 b6
B71 Levenfish Variation, Sicilian; B71 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.f4
C40 Levenstein; Queen's Defense; Brazilian; Gunderam 1.e4 e5 2.Nf3 Qe7
C23 Lewis Countergambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.c3 d5 4.Bxd5 Nf6
C23 Lewis Counter-Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.c3 d5
C53 Lewis Defense, Italian; Closed Variation 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Qe7
C23 Lewis Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.d4
C67 L'Hermet Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Nd6
C42 Lichtenhein Defense, Petroff 1.e4 e5 2.Nf3 Nf6 3.Bc4 Nxe4 4.Nc3 d5
A00 Liebig Gambit, Dunst 1.Nc3 e5 2.e3 d5 3.Qh5 Nf6
D44 Lilienthal Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7
D20 Linares Variation, QGA 1.d4 d5 2.c4 dxc4 3.e4 c5 4.d5 Nf6 5.Nc3 b5
A45 Linder Counter Gambit 1.d4 Nf6 2.f3 e6 3.e4 Nxe4
B00 Linksspringer Variation, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.d5
C41 Lion Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Nc3 Nf6
B07 Lion's Jaw, Pirc 1.e4 d6 2.d4 Nf6 3.f3
B90 Lipnitzky Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bc4
A42 Lisbon Gambit 1.d4 d6 2.c4 e5 3.dxe5 Nc6
A80 Lisbon Gambit, Dutch; Krejcik Gambit 1.d4 f5 2.g4
A06 Lisitsin Gambit Deferred, Zukertort 1.Nf3 f5 2.d3 Nf6 3.e4
A04 Lisitsin Gambit; Polish Gambit 1.Nf3 f5 2.e4  
A40 Lithuanian Variation, Mikenas 1.d4 Nc6 2.c4 e5 3.d5 Nce7
A40 Lizard Defense; Pirc-Diemer Gambit 1.d4 g6 2.h4 Nf6 3.h5
B28 Ljubojevic Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c3 b5
B09 Ljubojevic Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Bc4
C40 Lobster Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.g4
C41 Locock Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.Ng5 h6 5.Nxf7
D33 Lodz; Schlecter; Rubinstein Var, QGD; D33 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3
A10 Loehn Gambit, English 1.c4 d5 2.cxd5 e6
C57 Lolli Attack, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6.d4
C44 Lolli Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 Nxd4
C56 Loman Defense, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Bc5 6.e5 d5 7.exf6 dxc4 8.Re1+ Be6 9.Ng5 g6
A00 London Defense, Grob 1.g4 e5 2.h3 Nc6
C44 London Defense, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Bb4+
A46 London System 1.d4 Nf6 2.Nf3 e6 3.Bf4
A48 London System, Torre Attack 1.d4 Nf6 2.Nf3 g6 3.Bf4
D02 London System; Queen's Bishop Opening 1.d4 d5 2.Nf3 Nf6 3.Bf4
A09 London V; New York V, Reti 1.Nf3 d5 2.c4 c6 3.b3 Nf6 4.Bb2 Bf5
A48 London Variation 1.d4 Nf6 2.Nf3 g6 3.Bf4 Bg7 4.Nbd2
C39 Long Whip Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 h5
C41 Lopez Counter-Gambit, Philidor 1.e4 e5 2.Nf3 d6 3.Bc4 f5
C33 Lopez Defense, KGA 1.e4 e5 2.f4 exf4 3.Bc4 c6
C84 Lopez Four Knights, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Nc3
C23 Lopez Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.Qe2 Nf6 4.f4
C23 Lopez Variation, Bishop 1.e4 e5 2.Bc4 Bc5 3.Qe2
B58 Louma Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Be2 e5 7.Nxc6
C02 Lputian Variation, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.a3 Nh6
C50 Lucchini Gambit; Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d3 f5
C60 Lucena Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Be7
A40 Lundin Defense 1.d4 Nc6
D80 Lundin Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bg5 Ne4 5.Nxe4 dxc3 6.Qd2 c5
A56 Lundin; Bronstein Counter-Gambit 1.d4 Nf6 2.c4 c5 3.d5 d6 4.Nc3 g6 5.e4 b5
D47 Lundin; Neo-Meran 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 b4
B31 Lutikov Gambit, Sicilian 1.e4 c5 2.Nf3 Nc6 3.Bb5 g6 4.O-O Bg7 5.c3 Nf6 6.d4
D70 Lutikov Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.f3
C90 Lutikov Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.Bc2
C90 Lutikov Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d6 9.Bd2
C68 Lutikov Variation, Ruy Lopez Exchange 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 bxc6
C33 MacDonnell Attack, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Nc3 Bg7 6.d4 Ne7 7.g3
C23 MacDonnell Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.b4
C37 MacDonnell Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Nc3
C77 Mackenzie Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.d4
C20 Macleod Attack 1.e4 e5 2.c3
C34 MacLeod Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Nc6
C44 MacLopez; Relfsson Gambit, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bb5
D00 Mad Dog Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Bc4 Bg7 7.h4
A45 Maddigan Gambit 1.d4 Nf6 2.Nc3 e5
C30 Mafia Defense, KGD 1.e4 e5 2.f4 c5
C40 Mail Line, Latvian Gambit Accepted 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4
A57 Main Line, Benko Gambit Declined 1.d4 Nf6 2.c4 c5 3.d5 b5 4.Nf3
B52 Main Line, Canal Attack, Sicilian; B52 1.e4 c5 2.Nf3 d6 3.Bb5+ Bd7  
D19 Main Line, Czech Variation, Slav; D19 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.e3 e6 7.Bxc4 Bb4 8.O-O O-O 9.Qe2
C52 Main Line, Evans Gambit; C52 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5
D80 Makogonov Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.b4
D94 Makogonov Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.e3 O-O 6.b4
E71 Makogonov Variation, KID; E71 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.h3
C45 Malaniuk Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bb4+
A45 Malich Gambit 1.d4 Nf6 2.Nc3 d5 3.Bg5 c5 4.Bxf6 gxf6 5.e4 dxe4 6.d5
C83 Malkin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5
A45 Maltese Falcon 1.d4 Nf6 2.g4 Nxg4 3.f3 Nf6 4.e4
A10 Malvinas Variation, English 1.c4 d5 2.cxd5 Qxd5 3.Nc3 Qa5
A80 Manhattan Gambit, Dutch 1.d4 f5 2.Qd3 Nf6 3.g4
D51 Manhattan; Westphalia Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 Bb4
D23 Mannheim Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.Qa4+
B00 Mao Tse Tung; Duras 1.e4 f5
D18 Mareschall Variation, Slav; Lasker Variation 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.e3 Na6
B62 Margate (Vitolins) Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Bb5
A47 Marienbad Variation 1.d4 Nf6 2.Nf3 b6 3.g3 Bb7 4.Bg2 c5
B20 Marienbad Variation, Sicilian 1.e4 c5 2.b4 cxb4 3.a3 d5 4.exd5 Qxd5 5.Bb2
C25 Mariotti Gambit 1.e4 e5 2.Nc3 Nc6 3.g3 Bc5 4.Bg2 h5 5.Nf3 h4
B28 Maroczy Bind, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.c4
B36 Maroczy Bind, Sicilian; B36 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6 5.c4
B07 Maroczy Defense, Pirc 1.e4 d6 2.d4 e5
C40 Maroczy Gambit 1.e4 e5 2.Nf3 d5 3.exd5 Bd6
B12 Maroczy Gambit, Caro-Kann 1.e4 c6 2.d4 d5 3.f3 dxe4 4.fxe4 e5 5.Nf3 exd4 6.Bc4
B74 Maroczy Line, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O O-O 9.Nb3 Be6 10.f4 Na5
C49 Maroczy Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Ne2
B02 Maroczy Variation, Alekhine 1.e4 Nf6 2.d3
B12 Maroczy Variation, Caro 1.e4 c6 2.d4 d5 3.f3
C14 Maroczy Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4 a6
C40 Maroczy; Elephant Gambit 1.e4 e5 2.Nf3 d5 3.exd5 Bd6
C18 Maroczy-Willis Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3 cxd4 6.axb4 dxc3
C30 Marshall (Euwe) Attack, KGD 1.e4 e5 2.f4 Bc5 3.Nf3 d6 4.c3 Bg4 5.fxe5 dxe5 6.Qa4+
C89 Marshall Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5
C31 Marshall C-G, KGD 1.e4 e5 2.f4 d5 3.exd5 c6
C89 Marshall Counter-Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5 9.d4 
D06 Marshall Defense; Knight Defense, QGD 1.d4 d5 2.c4 Nf6  
C48 Marshall Gambit, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bc5 5.Nxe5 Nd4 6.Ba4 O-O
B00 Marshall Gambit, Nimzovich 1.e4 Nc6 2.d4 d5 3.exd5 Qxd5 4.Nc3
B01 Marshall Gambit, Scandanavian G; Modern Variation, CC 1.e4 d5 2.exd5 Nf6   
D31 Marshall Gambit, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.e4  
B23 Marshall Gambit, Sicilian 1.e4 c5 2.Nc3 e6 3.d4 d5
D32 Marshall Gambit, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.e4
C56 Marshall Variation, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Bc5 6.e5 d5 7.exf6 dxc4 8.Re1+ Be7 9.Ng5 Qd5 10.Nc3 Qf5
B01 Marshall Variation, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5
C10 Marshall Variation, French 1.e4 e6 2.d4 d5 3.Nc3 c5
C42 Marshall Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Bd6
B20 Marshall Variation, Sicilian 1.e4 c5 2.b4 cxb4 3.a3  
B41 Marshall Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 d5
B10 Masi Variation, Caro-Kann 1.e4 c6 2.d4 Nf6
D00 Mason Attack, Queen Pawn Game 1.d4 d5 2.f4
C40 Mason Countergambit, Latvian 1.e4 e5 2.Nf3 f5 3.d4
C54 Mason Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.O-O
C42 Mason Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Be7 7.O-O O-O
C42 Mason-Showalter Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6
B10 Massachussets Defense, Caro-Kann 1.e4 c6 2.d4 f5
B06 Masur Gambit 1.e4 g6 2.d4 Nh6 3.Nc3 f5 4.Bxh6 Bxh6 5.exf5 O-O
B82 Matanovic Attack, Sicilian; B82 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.f4
B00 Matovinsky Gambit 1.e4 b6 2.d4 Bb7 3.Bd3 f5
B00 Matovinsky Gambit 1.e4 b6 2.d4 Bb7 3.Bd3 f5 4.exf5 Bxg2 5.Qh5+ g6
B02 Matsukevich Gambit, Alekhine 1.e4 Nf6 2.e5 Nd5 3.c4 Nb6 4.c5 Nd5 5.Nc3 Nxc3 6.dxc3 d6 7.Bg5
A89 Matulovic Variation, Dutch; A89 1.d4 f5 2.c4 Nf6 3.g3 g6 4.Bg2 Bg7 5.Nf3 O-O 6.O-O d6 7.Nc3 Nc6
C33 Maurian Defense, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Nc6
C56 Max Lange Attack 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Bc5 6.e5
C40 Mayet Attack, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4  
C38 Mayet Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.d4 d6 6.c3
A22 Mazedonisch Variation, English 1.c4 e5 2.Nc3 Nf6 3.f4
C40 McConnell Defense 1.e4 e5 2.Nf3 Qf6
C12 McCutcheon Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4
C33 McDonnell Attack, KGA 1.e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4.Kf1 g5 5.Nc3 Bg7 6.g3  
D20 McDonnell Defense, QGA 1.d4 d5 2.c4 dxc4 3.e4 e5
C23 McDonnell Double Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.b4 Bxb4 4.f4
A39 Mecking Variation, Symmetrical English; A39 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3 Nf6 6.O-O O-O 7.d4
C01 Mediterranean Defense, French 1.e4 e6 2.d4 Nf6
A50 Medusa Gambit 1.d4 Nf6 2.c4 g5
C23 Meitner-Mieses Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.Bc4 Bc5 4.Qg4 Qf6 5.Nd5
A00 Melleby Gambit, Dunst 1.Nc3 d5 2.f4 d4 3.Ne4 c5
C20 Mellon Gambit 1.e4 e5 2.Qh5 Nc6 3.Bc4 Nh6 4.d3 g6 5.Qf3 f6 6.Ne2 d5
B20 Mengarini Gambit, Sicilian 1.e4 c5 2.a3  
B20 Mengarini Gambit, Sicilian 1.e4 c5 2.a3 Nc6 3.b4
C20 Mengarini Opening 1.e4 e5 2.a3
C26 Mengarini Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.a3
D47 Meran Variation, QGD; D47 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4
C53 Mestel Variation, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Qe7 5.d4 Bb6 6.Bg5
C49 Metger Unpin Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Bg5 Bxc3 8.bxc3 Qe7 9.Re1 Nd8
A09 Michel Gambit, Reti 1.Nf3 d5 2.c4 d4 3.b4 c5
C37 Middleton Counter-Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 d6 5.O-O Bg4 6.h3 h5 7.hxg4
C52 Mieses Defense, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4 7.O-O Nge7
B12 Mieses Gambit, Caro 1.e4 c6 2.d4 d5 3.Be3
B01 Mieses Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6
C45 Mieses Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.Nxc6
C26 Mieses Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.g3
D00 Mieses; Nimzovich Var, BDG 1.d4 d5 2.e4 dxe4 3.f3 Nc6
D00 Mieses; Nimzovich Var, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nc6 
A00 Mieses; Valencia; Venezuelan Opening 1.d3  
B01 Mieses-Kotroc Variation, Center Counter 1.e4 d5 2.exd5 Qxd5
C20 Miguel Gambit 1.e4 e5 2.Bb5 Bc5 3.b4
B02 Mikenas Gambit, Alekhine 1.e4 Nf6 2.e5 Nd5 3.c4 Nb6 4.c5 Nd5 5.Bc4 e6 6.Nc3 d6 7.Nxd5 exd5 8.Bxd5
A66 Mikenas V, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.e5
B00 Mikenas Variation, Nimzovich Defense 1.e4 Nc6 2.d4 d6
A15 Mikenas-Carls Variation, English 1.c4 Nf6
D45 Mikhalchishin Line, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Qc2 Bd6 7.e4 dxe4 8.Nxe4 Nxe4 9.Qxe4 e5 10.dxe5
D31 Miladinovic Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 Be7 4.e4 dxe4 5.f3
C30 Miles Defense, KGD 1.e4 e5 2.f4 Nc6 3.Nf3 f5
C31 Miles Gambit, KGD 1.e4 e5 2.f4 d5 3.exd5 Bc5
E12 Miles Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Bf4
C42 Millenium Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Bd3
C45 Millennium Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.c3 Qg6
B15 Milner-Barry Gambit, Caro; Rasa-Studier Gambit 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3
C02 Milner-Barry Gambit, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.Bd3
C02 Milner-Barry Gambit, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.Bd3 cxd3 7.cxd3 Bd7 8.O-O Nxd4 9.Nxd4
E33 Milner-Barry Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 Nc6 5.Nf3 d6
E33 Milner-Barry, Zurich Variation, Nimzo-Indian; E33 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 Nc6
C67 Minckwitz Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.dxe5
B11 Mindeno Variation, Caro-Kann 1.e4 c6 2.Nc3 d5 3.Nf3 Bg4
B06 Mittenberger Gambit, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nc3 d5
C40 Mlotkowski Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Nc3
C43 Modern Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4
A60 Modern Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6
C55 Modern Bishop's Opening 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3
A40 Modern Defense 1.d4 g6 2.c4 Bg7 3.Nc3 d6
E76 Modern Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 Na6
D78 Modern Defense, Neo-Grunfeld 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O dxc4
D20 Modern Defense, QGA 1.d4 d5 2.c4 dxc4 3.e4 Nc6
C45 Modern Defesne, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Nc3 Bb4
D06 Modern Gambit, Chigorin Defense 1.d4 d5 2.c4 Nc6 3.Nc3 Nf6 4.Nf3 dxc4
D11 Modern Line, Slav; D11 1.d4 d5 2.c4 c6 3.Nf3
D85 Modern Main Line, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Nf3
B84 Modern Paulsen, Sicilian; B84 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be2 a6
E05 Modern Sharp Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bb4+
C71 Modern Steinitz Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6
C32 Modern Transfer, Falkbeer Countergambit, KGD 1.e4 e5 2.f4 d5 3.exd5 exf4
A57 Modern Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.e3
B12 Modern Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.Nd2
A01 Modern Variation, Larsen 1.b3 e5
D50 Modern Variation, QGD; D50 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5
B50 Modern Variation, Sicilian; B50 1.e4 c5 2.Nf3 d6
C27 Modern Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4
B10 Modern; English Variation, Accelerated Panov; Caro-Kann 1.e4 c6 2.c4
C63 Moehring Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 fxe4 5.Nxe4 d5 6.Nxe5 dxe4 7.Nxc6 Qd5
C54 Moeller (Therkatz) Attack, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Nc3 Nxe4 8.O-O Bxc3 9.d5
C78 Moeller Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Bc5
B02 Mokele Mbembe; Knight's Tour 1.e4 Nf6 2.e5 Ne4
B27 Mongoose Variation, Sicilian 1.e4 c5 2.Nf3 Qa5
B06 Mongredien Defense, Pirc 1.e4 g6 2.d4 Bg7 3.Nf3 b6
B06 Monkey's Bum, Pirc 1.e4 g6 2.Bc4 Bg7 3.Qf3 e6 4.d4
C27 Monster Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nxe4 4.Qh5 Nd6 5.Bb3 Be7
C01 Monte Carlo Variation, French 1.e4 e6 2.d4 d5 3.exd5 exd5 4.c4
A40 Montevideo Defense 1.d4 Nc6 2.d5 Nb8
E11 Monticelli Trap 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ 4.Bd2 Bxd2+ 5.Qxd2 b6 6.g3 Bb7 7.Bg2 O-O 8.Nc3 Ne4 9.Qc2 Nxc3 10.Bg5
C42 Moody Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Qe2 Nc6 4.d4
C40 Morgado Defense, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4 Nf6
C03 Morozevich Variation, French 1.e4 e6 2.d4 d5 3.Nd2 Be7
C51 Morphy Attack, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6 9.Nc3  
B20 Morphy Defense Deferred, Smith-Morra Accepted 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 a6 7.O-O b5 8.Bb3 Bc5
C32 Morphy Defense, KGD 1.e4 e5 2.f4 d5 3.exd5 e4 4.d3 Nf6 5.Nc3 Bb4 6.Bd2 e3
C68 Morphy Defense, Ruy Lopez; C68 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6
C70 Morphy Defense, Ruy Lopez; C70 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4
B20 Morphy Defense, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Bc5
C01 Morphy Gambit, French 1.e4 e6 2.d4 d5 3.Nh3
C41 Morphy Gambit, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4 4.Bc4
B20 Morphy Gambit, Sicilian 1.e4 c5 2.d4 cxd4 3.Nf3
D00 Morris Counter-Gambit 1.d4 d5 2.Bf4 c5 3.e4 dxe4
D00 Morris Gambit 1.d4 d5 2.Bf4 c5 3.e4  
C65 Mortimer Trap, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d3 Ne7 5.Nxe5 c6
C65 Mortimer Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d3 Ne7
B55 Moscow (Prins) Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.f3
B51 Moscow Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.Bb5+ Nc6 4.O-O Bd7 5.c3 a6 6.Bxc6 Bxc6 7.Re1 Nf6 8.d4 Bxe4 9.Bg5
C17 Moscow Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.Qg4
B51 Moscow Variation, Sicilian; Canal Attack; B51 1.e4 c5 2.Nf3 d6 3.Bb5+
A40 Mosquito Gambit, Englund 1.d4 e5 2.dxe5 Qh4
C82 Motzko Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5 10.Qd3
A02 Mujannah Opening 1.f4 Nf6 2.c4
D70 Murey Attack, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.f3 c5 5.cxd5 Nxd5 6.Na4
E12 Murey Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.a3 Bb7 5.Nc3 d5 6.cxd5 Nxd5 7.Qc2 c5 8.e4 Nxc3 9.bxc3 Nc6 10.Bb2 cxd4 11.cxd4 Rc8 12.Rd1 Bd6
C43 Murret Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 Nxe4 4.Bd3 Nc6
A57 Mutkin Countergambit, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.g4
C37 Muzio-Polerio Gambit, KGA; Wild Muzio 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O
B20 Myers Attack, Sicilian 1.e4 c5 2.h4
A02 Myers Defense, Bird 1.f4 b5
A10 Myers Defense, English 1.c4 g5 2.d4 Bg7
A00 Myers Defense, Hungarian 1.g3 g5
B02 Myers Gambit, Alekhine 1.e4 Nf6 2.Nc3 d5 3.d3 dxe4 4.Bg5
A00 Myers Gambit, Dunst 1.Nc3 d5 2.e4 dxe4 3.Nxe4 e5 4.Bg5
A00 Myers Gambit, Kadas 1.h4 d5 2.d4 c5 3.e4
A05 Myers Polish Attack 1.Nf3 Nf6 2.a4 g6 3.b4
A00 Myers Variation, Polish 1.b4 d5 2.Bb2 c6 3.a4
C56 Nachmanson Gambit, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4 6.Nc3
D85 Nadanian Attack 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.Na4
B90 Najdorf Variation, Sicilian; B90 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6
C20 Napoleon Attack 1.e4 e5 2.Qf3
A00 Napoleon Attack, Dunst 1.Nc3 e5 2.Nf3
A00 Napoleon Attack, Dunst 1.Nc3 e5 2.Nf3 Nc6 3.d4
C44 Napoleon Gambit, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 Nxd4 4.Nxd4 exd4 5.Bc4
A30 Napolitano Gambit, Symmetrical English 1.c4 c5 2.Nf3 Nf6 3.b4
B00 Naselwaus Variation, Owen's Defense 1.e4 b6 2.d4 Bb7 3.Bg5
A19 Nei Gambit, English 1.c4 Nf6 2.Nc3 e6 3.e4 c5 4.e5 Ng8
C82 Nenarokov Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5 10.Qd3 Ne7
A13 Neo Catalan Accepted, English 1.c4 e6 2.Nf3 d5 3.g3 Nf6 4.Bg2 dxc4
A14 Neo Catalan Declined, English 1.c4 e6 2.Nf3 d5 3.g3 Nf6 4.Bg2 Be7 5.O-O
A13 Neo Catalan, English 1.c4 e6 2.Nf3 d5 3.g3 Nf6
D55 Neo Orthodox Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6
A09 Neo-Catalan, Reti 1.Nf3 d5 2.c4 e6 3.g3
C35 Neo-Cunningham Gambit, KGA; McCormick Defense 1.e4 e5 2.f4 exf4 3.Nf3 Be7 4.Bc4 Nf6
D70 Neo-Grunfeld Defense 1.d4 Nf6 2.c4 g6 3.Nf3 d5
A40 Neo-Modern Defense 1.d4 g6 2.c4 Bg7 3.e4 e5
B00 Neo-Mongoloid Defense, Nimzovich 1.e4 Nc6 2.d4 f6
D54 Neo-Orthodox Variation, QGD; D54 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Rc1
C78 Neo-Steinitz Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 d6
A57 Nescafe Frappe Attack, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.Nc3 axb5 6.e4 b4 7.Nb5
D00 Netherlands Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 f5
C39 Neumann Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nc6
C44 Neumann Gambit, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 Nf6 4.Bc4
B12 New Caro-Kann 1.e4 c6 2.d4 d5 3.Nd2 g6
C70 Nightingale Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5 5.Bb3 Na5 6.Bxf7+
C44 Nikitin Gambit, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Bb5 dxe4 5.Nxe5 Qd5 6.Qa4
A90 Nimzo-Dutch Variation 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Bb4+
A17 Nimzo-English Opening 1.c4 Nf6 2.Nc3 e6 3.Nf3 Bb4
E20 Nimzo-Indian Defense 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4
D00 Nimzovich Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Bc4 Bg7 7.Ne5
C02 Nimzovich Attack, French 1.e4 e6 2.d4 d5 3.e5 c5 4.Qg4
C40 Nimzovich Attack, Latvian 1.e4 e5 2.Nf3 f5 3.Nxe5 Qf6 4.d4 d6 5.Nc4 fxe4 6.Ne3
C42 Nimzovich Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3
E15 Nimzovich Attack, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6 5.Qa4+
C62 Nimzovich Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 d6 4.d4 Bd7 4.Nc3 Nf6 5.Bxc6
D70 Nimzovich Attack; Anti-Grunfeld; Alekhine Variation 1.d4 Nf6 2.c4 g6 3.f3
B00 Nimzovich Defense 1.e4 Nc6
B00 Nimzovich Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3 dxe4 4.d5 Ne5
A06 Nimzovich Opening, Reti; Nimzovich-Larsen Attack 1.Nf3 d5 2.b3
E11 Nimzovich Variation, Bogo-Indian 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+ 4.Bd2 Qe7
A83 Nimzovich Variation, Dutch 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.Bg5 b6
A20 Nimzovich Variation, English 1.c4 e5 2.Nf3
C02 Nimzovich Variation, French 1.e4 e6 2.d4 d5 3.e5 c5 4.Nf3
C31 Nimzovich Variation, KGD; Anderssen Attack 1.e4 e5 2.f4 d5 3.exd5 e4 4.Bb5+
A61 Nimzovich Variation, Knight's Tour Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.Nd2
E15 Nimzovich Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6
B32 Nimzovich Variation, Sicilian; Nimzo-American Variation 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 d5
A46 Nimzovich Variation, Torre Attack 1.d4 Nf6 2.Nf3 e6 3.Bg5 h6
B16 Nimzovich; Bronstein-Larsen, Caro; B16 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Nxf6+ gxf6
B29 Nimzovich; Rubinstein Var, Sicilian; B29 1.e4 c5 2.Nf3 Nf6
C77 Nimzovich; Tarrasch Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.Nc3
A20 Nimzovich-Flohr Variation, English 1.c4 e5 2.Nf3 e4
C31 Nimzovich-Marshall Variation, KGD 1.e4 e5 2.f4 d5 3.exd5 c6
C47 Noa Gambit, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bc4 Nxe4 5.Bxf7+
E34 Noa Variation, Nimzo-Indian; E34 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5
C71 Noah's Ark Trap, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.d4 b5 6.Bb3 exd4 7.Nxd4 Nxd4 8.Qxd4 c5 9.Qd5 Be6 10.Qc6+ Bd7
B02 Noch Gambit, Alekhine 1.e4 Nf6 2.Nc3 d5 3.exd5
E81 Normal Defesne, Sameisch Variation, KID; E81 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O
D08 Normal Line, Albin Countergambit, QGD 1.d4 d5 2.c4 e5 3.dxe5 d4 4.Nf3
C51 Normal Position, Evans Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6
B28 Normal System, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d4
A52 Normal Variation, Budapest; A52 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4
A85 Normal Variation, Dutch 1.d4 f5 2.c4 Nf6
C10 Normal Variation, French; C10 1.e4 e6 2.d4 d5 3.Nc3
A50 Normal Variation, Indian Game; A50 1.d4 Nf6 2.c4
E97 Normal Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7
E70 Normal Variation, KID; E70 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4
E46 Normal Variation, Nimzo-Indian; E46 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O
A55 Normal Variation, Old Indian; A55 1.d4 Nf6 2.c4 d6 3.Nc3 e5 4.Nf3 Nbd7 5.e4
C78 Normal Variation, Ruy Lopez; C78 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O
D45 Normal Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7
A34 Normal Variation, Symmetrical English; A34 1.c4 c5 2.Nc3
C30 Norwalde (Norwalder) Variation, KGD 1.e4 e5 2.f4 Qf6
C20 Norwalder Gambit 1.e4 e5 2.c3 d5 3.Qh5 Bd6
B06 Norwegian Defense 1.e4 g6 2.d4 Nf6
D31 Noteboom Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.Nf3 dxc4
B72 Nottingham Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.Nb3
D20 Novikov Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e3 e5 4.Bc4 exd4 5.Qb3 Qe7 6.Nd2
A00 Novosibirsk Variation, Dunst 1.Nc3 c5 2.d4 cxd4 3.Qxd4 Nc6 4.Qh4
A00 Nowokunski Gambit, Dunst 1.Nc3 e5 2.f4 exf4 3.e4
C60 Nuremberg Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f6
C65 Nyholm Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.d4 exd4 5.O-O
A04 Oberndorfer Gambit; Reti 1.Nf3 g5
D00 O'Kelly Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 c6 
E26 O'Kelly Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.e3 b6
B28 O'Kelly Variation, Sicilian; B28 1.e4 c5 2.Nf3 a6
E48 Olafsson Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.Nf3 c5 7.O-O dxc4 8.Bxc4 b6 9.Qe2 Bb7 10.Rd1 Qc8
A43 Old Benoni 1.d4 c5 2.d5 d6
A06 Old Indian Attack 1.Nf3 d5 2.d3
A53 Old Indian Defense; Chigorin Indian Defense; A53 1.d4 Nf6 2.c4 d6
C32 Old Line, Falkbeer Countergambit, KGD 1.e4 e5 2.f4 d5 3.exd5 e4 4.d3 Nf6 5.Qe2
D48 Old Meran Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.O-O
B30 Old Sicilian 1.e4 c5 2.Nf3 Nc6
D20 Old Variation, QGA 1.d4 d5 2.c4 dxc4 3.e3
D48 Old Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 c5 10.e5
E33 Old Zurich Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 Nc6 5.Nf3 d6 6.a3
C12 Olland (Dutch) Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Bc1
C25 Omaha Gambit, Vienna 1.e4 e5 2.Nc3 d6 3.f4
A45 Omega Gambit 1.d4 Nf6 2.e4
A08 Omega-Delta Gambit, KIA 1.Nf3 d5 2.g3 e5
E04 Open Defense, Catalan; E04 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Nf3
C07 Open System Tarrasch French; C07 1.e4 e6 2.d4 d5 3.Nd2 c5
C56 Open Variation, Two Knights Defense; C56 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4
D80 Opocensky Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Bd2
D94 Opocensky Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.e3 O-O 6.Bd2
E17 Opocensky Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.Nc3 Ne4 7.Bd2
B92 Opocensky Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be2 e5
B92 Opocensky Variation, Sicilian; B92 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be2
D78 Original Defesne, Neo-Grunfeld; D78 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O c6
C33 Orsini Gambit, KGA 1.e4 e5 2.f4 exf4 3.b3
E85 Orthodox Variation, KID; E85 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 e5
E91 Orthodox Variation, KID; E91 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2
D60 Orthodox Variation, QGD; D60 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7
C00 Orthoschapp Variation, French 1.e4 e6 2.c4 d5 3.cxd5 exd5 4.Qb3
A45 Oshima Defense 1.d4 Nf6 2.g4 e5
A00 Outflank Variation, Polish 1.b4 c6   
B00 Owen's Defense; Greek Defense 1.e4 b6
C47 Oxford Gambit, Four Kngihts 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 Bb4 5.d5 Nd4
C26 Oxford Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.d3
A85 Ozol Variation, Dutch 1.d4 f5 2.c4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.Bg5
D80 Pachman Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Qb3 dxc4 7.Bxc4 Nbd7 8.Ng5
A45 Paleface Attack 1.d4 Nf6 2.f3
E83 Panno Formation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 Nc6 7.Nge2 a6
E60 Panno System 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.O-O Nc6 7.d5 Na5
E60 Panno Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 Nc6 7.O-O a6 8.h3 Rb8
E63 Panno Variation, KID; E63 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nc6 7.O-O a6
E41 Panov Attack, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Nf3 cxd4 6.exd4 d5
B01 Panov Transfer, Center Counter 1.e4 d5 2.exd5 Nf6 3.c4 c6
B04 Panov Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Bg4 5.h3
B76 Panov Variation, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.g4
B07 Panov; Opatijav; Byrne Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5
B13 Panov-Botvinnik; Gunderam Attack 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4
C30 Panteldakis Countergambit, KGD 1.e4 e5 2.f4 f5
C00 Papa-Ticulat Gambit, French 1.e4 e6 2.b3 d5 3.Bb2
A00 Paris Gambit 1.Nh3 d5 2.g3 e5 3.f4
C33 Paris Gambit, KGA 1.e4 e5 2.f4 exf4 3.Ne2
D80 Paris Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Bd3
B08 Parma Defense, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.Be2 O-O 6.O-O Bg4
C44 Paschman Wing Gambit 1.e4 e5 2.Nf3 Nc6 3.b4
C23 Paschmann Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.Ne2 Nxe4 4.Nec3
A01 Paschmann Gambit, Larsen 1.b3 e5 2.Bb2 Nc6 3.f4
C22 Paulsen Attack Variation, Center 1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qe3  
C02 Paulsen Attack, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3
B00 Paulsen Attack, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 Nxe5 4.Nf3
C42 Paulsen Attack, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nc4
C41 Paulsen Attack, Philidor 1.e4 e5 2.Nf3 d6 3.d4 exd4 4.Nxd4 d5 5.exd5
C45` Paulsen Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Be3 Qf6 6.c3 Nge7 7.Bb5
C29 Paulsen Attack, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.Qf3
C40 Paulsen Counter-Gambit 1.e4 e5 2.Nf3 d5 3.exd5 e4
C39 Paulsen Defense Deferred, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bg7
C37 Paulsen Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6 7.e5 Qxe5 8.d3 Bh6 9.Nc3 Ne7 10.Bd2
C39 Paulsen Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Bg7
C25 Paulsen Defense, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.d4 Qh4+ 5.Ke2 d6
B20 Paulsen Formation, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 a6
B28 Paulsen Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c4 e6
C49 Paulsen Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.Bxc6
C60 Paulsen Variation, Cozio Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nge7 4.Nc3 g6
C51 Paulsen Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6 9.d5 Na5 10.Bb2 Ne7
C61 Paulsen Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nd4 4.Nxd4 exd4 5.O-O Ne7
C45 Paulsen Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Nf5
B85 Paulsen Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be2 a6 7.O-O Qc7 8.f4 Nc6
B45 Paulsen Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Nf6 6.Ndb5 Bb4
C25 Paulsen Variation, Vienna 1.e4 e5 2.Nc3 Nc6 3.g3
C44 Paulsen; Anderssen C-A, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Bc5 5.O-O d6 6.c3 Bg4
B41 Paulsen; Kan Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6
A45 Pawn Push Variation 1.d4 Nf6 2.d5
A57 Pawn Return Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.b6
A66 Pawn Storm Variation, Benoni; A66 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4
A02 Pawn Thrust Attack, Bird 1.f4 f5 2.d4 d5
A44 Pawn Thrust, Benoni; A44 1.d4 c5 2.d5 e5
C00 Pelikan Variation, French 1.e4 e6 2.Nc3 d5 3.f4
B33 Pelikan Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6
A09 Penguin Variation, Reti 1.Nf3 d5 2.c4 d4 3.Rg1
A61 Penrose Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.Bd3
B81 Perenyi Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be3 a6 7.g4 e5 8.Nf5 g6 9.g5
C56 Perreux Variation, Two Knights Defense 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.Ng5
A40 Perrin Variation 1.d4 e6 2.c4 b6 3.e4 Bb7 4.Bd3 Nc6
C01 Perseus Gambit, French 1.e4 e6 2.d4 d5 3.Nf3
D00 Peters Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Ne5
C42 Petroff Defense; Russian Defense; C42 1.e4 e5 2.Nf3 Nf6
A46 Petrosian Gambit 1.d4 Nf6 2.Nf3 e6 3.Bg5 c5 4.e3 b6 5.d5
D91 Petrosian System, Grunfeld; D91 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Bg5
A56 Petrosian System; Czech Benoni Defense 1.d4 Nf6 2.c4 c5 3.d5 e5
C16 Petrosian Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 Qd7
E92 Petrosian Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.d5
D55 Petrosian Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bxf6 Bxf6 8.Rc1 c6 9.Bd3 Nd7 10.O-O dxc4
E12 Petrosian Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.a3
C30 Petrov's Defense, KGD 1.e4 e5 2.f4 Nf6
A00 Pfeiffer Gambit, Dunst 1.Nc3 d5 2.f4 d4 3.Ne4 e5
D00 Pfrang Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 e6 5.fxe4 Bb4 6.Bd3 Bxc3+ 7.bxc3 Nxe4 8.Be3
C41 Philidor Counter Attack 1.e4 e5 2.Nf3 d6 3.d4 f5
C25 Philidor Countergambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.d4 f5
C41 Philidor Defense; C41 1.e4 e5 2.Nf3 d6
C21 Philidor Gambit 1.e4 e5 2.d4 d6 3.dxe5 Bd7
C41 Philidor Gambit 1.e4 e5 2.Nf3 d6 3.d4 Bd7
C38 Philidor Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.h4
B07 Philidor Gambit, Pirc 1.e4 d6 2.d4 e5 3.dxe5 Bd7
C23 Philidor Variation, Bishop 1.e4 e5 2.Bc4 Bc5 3.c3
B00 Pickering (Goldsmith) Defense 1.e4 h5
B00 Picklepuss Defense 1.e4 h5 2.d4 Nf6
C31 Pickler Gambit, KGD 1.e4 e5 2.f4 d5 3.exd5 c6 4.dxc6 Bc5
C52 Pierce Defense, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4
C25 Pierce Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.Nf3 g5 5.d4
D00 Pietrowsky Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Nc6
D55 Pillsbury Attack, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 b6 7.Bd3 Bb7 8.cxd5 exd5 9.Ne5
A41 Pillsbury Defense; A41; Rat Defense 1.d4 d6  
C49 Pillsbury Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6 7.Bg5 Ne7
D63 Pillsbury Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 b6 8.cxd5 exd5 9.Bd3
C67 Pillsbury Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 Nd6 7.Bxc6+ bxc6 8.dxe5 Nb7 9.b3
D40 Pillsbury Variation, Semi-Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.Bg5
C90 Pilnik Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.d3
D12 Pin Defense, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bg4
B20 Pin Defense, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Bb4
B41 Pin Variation; Sicilian CounterAttack 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Bb4
C00 Pinova Gambit 1.e4 e6 2.b4 Bxb4 3.e5
B00 Pirc Connection, Nimzovich Defense 1.e4 Nc6 2.d4 g6
B07 Pirc Defense 1.e4 d6 2.d4 Nf6
E39 Pirc Variation, Nimzo-Indian; E39 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 c5 5.dxc5 O-O
D48 Pirc Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 b4
B06 Pirc; Robatsch; Modern; King Pawn Fianchetto; B06 1.e4 g6
B07 Pirc; Ufimtsev; Antal Defense 1.e4 d6 2.d4 Nf6 3.Nc3 g6
A02 Platz Gambit, Bird 1.f4 e5 2.fxe5 Ne7 
B62 Podebrady Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Nb3
D00 Pohlmann Variation, BDG 1.d4 d5 2.e4 dxe4 3.f3 f5
B97 Poisoned Pawn Accepted, Najdorf Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Qb6 8.Qd2 Qxb2
C19 Poisoned Pawn Variation, French Winawer 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3 Bxc3+ 6.bxc3 Ne7 7.Qg4
C40 Poisoned Pawn Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Qg5 5.d4 Qxg2
B97 Poisoned Pawn Variation, Najdorf Sicilian; B97 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Qb6
D02 Poisoned Pawn Variation, QP 1.d4 d5 2.Nf3 Nf6 3.Bf4 c5 4.e3 Qb6 5.Nc3
B97 Poisoned Pawn Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Qb6 8.Qd2
A45 Poisoned Pawn Variation, Trompowsky 1.d4 Nf6 2.Bg5 c5 3.d5 Qb6 4.Nc3
C58 Polerio Defense, Two Knights; C58 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5
C40 Polerio-Svedenborg Variation, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 d5 
D78 Polgar Variation, Neo-Grunfeld 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O Nc6
A40 Poli Gambit 1.d4 e6 2.c4 b6 3.e4 Bb7 4.f3 f5 5.exf5 Nh6
D00 Polish Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e6 4.f3 Bf5 5.Bg5
A40 Polish Defense 1.d4 b5  
A46 Polish Defense 1.d4 Nf6 2.Nf3 b5
A04 Polish G; Dalesio G; Pirc-Lisitsin G 1.Nf3 f5 2.e4 fxe4 3.Ng5
A00 Polish Gambit, Anderssen's Opening 1.a3 a5 2.b4
D00 Polish Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3
B27 Polish Gambit, Sicilian 1.e4 c5 2.Nf3 b5
A00 Polish Spike 1.b4 Nf6 2.Bb2 g6 3.g4
A40 Polish Variation 1.e4 g6 2.d4 Bg7 3.c4 c5 4.Nf3 Qb6
B00 Polish Variation, St George Defense 1.e4 a6 2.d4 b5 3.Nf3 Bb7 4.Bd3 e6
A00 Polish; Orangutan; Sokolsky; Hunt 1.b4
C14 Pollock Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7 7.Qg4
C25 Polluck Gambit, Vienna 1.e4 e5 2.Nc3 Nf6 3.g3 Bc5 4.Bg2 Nc6 5.Nge2 d5 6.exd5
E12 Polovodin Gambit, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb7 5.a3 d5 6.cxd5 Nxd5 7.e4
E17 Polugaevsky Gambit, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.d5 exd5 8.Nh4
B42 Polugaevsky Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Bd3 Bc5
B96 Polugaevsky; Accelerated Najdorf 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 b5
E72 Pomar System, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.g3 O-O 6.Bg2 e5 7.Nge2
E60 Pomar Variation, KID 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 O-O 5.Nge2
B47 Ponomariov Gambit, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Qc7 6.Ndb5 Qb8 7.Be3 a6 8.Bb6
C24 Ponziani Center Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.d4 
C44 Ponziani Counter-Gambit 1.e4 e5 2.Nf3 Nc6 3.c3 f5
C44 Ponziani; Staunton; English Knights 1.e4 e5 2.Nf3 Nc6 3.c3  
C57 Ponziani-Steintz Gambit, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Nxe4
A10 Porcupine Variation, English 1.c4 f5 2.e4 fxe4 3.Nc3 Nf6 4.g4
D31 Portisch Gambit, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.e3 f5 5.g4
B23 Portland Attack, Sicilian 1.e4 c5 2.Nc3 Nc6 3.d3 g6 4.g4
B01 Portuguese Gambit, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Bg4 4.f3 Bf5 5.Bb5+ Nbd7
C20 Portuguese Opening 1.e4 e5 2.Bb5
B01 Portuguese Variation, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Bg4
D35 Positional Variation, Exchange Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5
A06 Potato, Zukertort 1.Nf3 d5 2.a4
C45 Potter Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Nb3
A40 Pozarek Gambit 1.d4 Nc6 2.c4 e5 3.dxe5 Nxe5 4.Nc3 Nxc4
D33 Prague Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6
A80 Pretzel Gambit, Dutch 1.d4 f5 2.Qd3 Nf6 3.g4
D21 Prianishenmo Gambit, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 c5 4.d5 Nf6 5.Nc3 e6 6.e4 exd5 7.e5
A24 Prickly Pawn Pass System, English 1.c4 e5 2.Nc3 Nf6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 6.e4 O-O 7.Nge2 c6 8.O-O a6
D50 Primitive Pillsbury Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 c5 5.Nf3 cxd4 6.Qxd4
B12 Prins Attack, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.b4
D97 Prins Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Na6
A03 Prokofiev Gambit, Bird 1.f4 d5 2.e4 dxe4 3.d3
C47 Provincial Opening, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d6 5.h3
C57 Prussian Game; Knight Attack, Two Knights; C57 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5
A49 Przepiorka Variation; A49 1.d4 Nf6 2.Nf3 g6 3.g3
B06 Pseudo-Austrian Attack 1.e4 g6 2.d4 Bg7 3.Nc3 d6 4.f4
A46 Pseudo-Benko Gambit 1.d4 Nf6 2.Nf3 c5 3.d5 b5
D02 Pseudo-Catalan 1.d4 d5 2.Nf3 Nf6 3.g3
D06 Pseudo-Chigorin, QGD 1.d4 d5 2.c4 Bf5 3.Nc3 e6 4.Nf3 Nc6
A00 Pseudo-Diemer Gambit, Dunst 1.Nc3 d5 2.e4 dxe4 3.f3 exf3 4.Qxf3
A48 Pseudo-King's Indian Variation; A48 1.d4 Nf6 2.Nf3 g6
C88 Pseudo-Marshall Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 Bb7 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5
D30 Pseudo-Meran; Semi-Slav, QGD 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.e3 c6
A40 Pseudo-Saemisch 1.d4 g6 2.c4 Bg7 3.e4 d6 4.Be3 Nf6 5.f3
A57 Pseudo-Saemisch, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.f3
D06 Pseudo-Slav, QGD 1.d4 d5 2.c4 Bf5 3.Nc3 e6 4.Nf3 c6
B00 Pseudo-Spanish Variation 1.e4 Nc6 2.Bb5
D50 Pseudo-Tarrasch Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 c5 5.cxd5  
D30 Pseudo-Tarrasch, QGD 1.d4 d5 2.c4 e6 3.Nf3 c5
A41 Pterodactyl Variation, Modern 1.d4 g6 2.c4 Bg7 3.Nc3 d6 4.e4 c5 5.Nf3 Qa5
B06 Pterodactyl, Pirc 1.e4 g6 2.d4 Bg7 3.Nc3 c5
B20 Push Variation, Smith-Morra Gambit, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 d3
A50 Pyrenees Gambit 1.d4 Nf6 2.c4 b5
C37 Quaade; Taylor Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Nc3
D06 Queen Attack, Baltic Defens, QGD 1.d4 d5 2.c4 Bf5 3.Nc3 e6 4.Qb3
B20 Queen Fianchetto Variation, Sicilian 1.e4 c5 2.b3 b6
A40 Queen Fianchetto, Queen Pawn Game 1.d4 b6
A06 Queen Pawn Defense, Zukertort; A06 1.Nf3 d5
A40 Queen Pawn Fianchetto 1.d4 g6
D00 Queen Pawn Game; Close Opening; D00 1.d4 d5
A40 Queen Pawn Opening; A40 1.d4
D25 Queen's Gambit Accepted Deferred 1.d4 d5 2.Nf3 Nf6 3.c4 dxc4
D20 Queen's Gambit Accepted; D20 1.d4 d5 2.c4 dxc4  
D02 Queen's Gambit Reversed; Krause Variation 1.d4 d5 2.Nf3 c5
D06 Queen's Gambit; Aleppo Gambit; D06 1.d4 d5 2.c4
E12 Queen's Indian Defense; E12 1.d4 Nf6 2.c4 e6 3.Nf3 b6
A50 Queen's Indian Defense; Saemisch-Indian 1.d4 Nf6 2.c4 b6
A18 Queen's Indian Formation, English 1.c4 Nf6 2.Nc3 e6 3.Nf3 b6
C30 Queen's Knight Defense, KGD 1.e4 e5 2.f4 Nc6
A84 Queen's Knight Variation, Dutch 1.d4 f5 2.c4 Nf6 3.Nc3
D31 Queen's Knight Variation, QGD; D31 1.d4 d5 2.c4 e6 3.Nc3
C00 Queen's Knight, French 1.e4 e6 2.Nc3
C40 Queen's Pawn Counter-Gambit; Elephant Gambit 1.e4 e5 2.Nf3 d5
C25 Quelle Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 Bc5 4.fxe5 d6
A57 Quiet Line, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.Nd2
A28 Quiet Line, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.e3
E15 Quiet Line, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6 5.b3
B28 Quiet System, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d3
B08 Quiet System, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.Be2
D30 Quiet Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.e3 c6 5.Nbd2
D11 Quiet Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3
B27 Quinteros Variation, Sicilian 1.e4 c5 2.Nf3 Qc7
C20 Radisch Gambit 1.e4 e5 2.d3 Nf6 3.f4 Bc5
E40 Ragozin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 Nc6 5.Nf3 O-O 6.Bd3 d5 7.O-O dxc4
E20 Ragozin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 d5
E51 Ragozin Variation, Nimzo-Indian; E51 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5
D38 Ragozin Variation, QGD; D38 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 Bb4
A42 Randspringer Variation 1.d4 g6 2.c4 Bg7 3.Nc3 d6 4.e4 f5
C48 Ranken Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 a6 5.Bxc6
A80 Raphael Variation, Dutch 1.d4 f5 2.Nc3
A45 Raptor Variation, Trompowsky 1.d4 Nf6 2.Bg5 Ne4 3.h4
C10 Rasa-Studier Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Be3
D00 Rasa-Studier Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e6 4.Be3
D00 Rasmussen Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e5 4.Nge2
D60 Rauzer Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Qb3
C98 Rauzer Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.Nbd2 Nc6 13.dxe5 dxe5 14.a4
B63 Rauzer Variation, Sicilian; B63 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2
A00 Regan Variation 1.g3 d5 2.Bg2 e5 3.d4
B14 Reifir-Spielmann Line, Caro-Kann 1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nc3 Nc6 6.Bg5 Qb6
C41 Rellstab Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.dxe5 Nxe4 5.Qd5
C33 Requena Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nc3 Qh4+
D83 Reshevsky Gambit, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bf4 Bg7 5.e3 O-O 6.Rc1 c5 7.dxc5 Qa5
E46 Reshevsky Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Ne2
E46 Reshevsky Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nge2
D36 Reshevsky Variation, QGD; D36 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5 c6 6.Qc2
C32 Reti (Charousek) Variation, KGD 1.e4 e5 2.f4 d5 3.exd5 e4 4.d3  
C00 Reti (Horwitz) Variation, French 1.e4 e6 2.b3
A09 Reti Gambit Accepted 1.Nf3 d5 2.c4 dxc4
A09 Reti Polonaise 1.Nf3 d5 2.c4 d4 3.b4
B28 Reti System, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.g3
D34 Reti Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.dxc5 Bxc5 10.Na4
B41 Reti Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.c4
A09 Reti; Landstrasser G; Wolf G; A09 1.Nf3 d5 2.c4  
A04 Reti; Zukertort; A04 1.Nf3  
C00 Reti-Spielmann Attack, French 1.e4 e6 2.g3
B11 Retreat Line, Mindeno Variation, Caro-Kann 1.e4 c6 2.Nc3 d5 3.Nf3 Bg4 4.h3 Bh5
C60 Retreat Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nc8
B32 Retreat Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Nf3
B02 Retreat; Brooklyn Variation, Alekhine 1.e4 Nf6 2.e5 Ng8
C00 Reuter Gambit, French 1.e4 e6 2.f4 d5 3.Nf3 dxe4 4.Ng5
A00 Reversed Alekhine 1.g3 e5 2.Nf3
A45 Reversed Chigorin Defense 1.d4 Nf6 2.Nc3 c5
A25 Reversed Closed Sicilian, English; A25 1.c4 e5 2.Nc3 Nc6
A23 Reversed Dragon, English 1.c4 e5 2.Nc3 Nf6 3.g3 d5
A06 Reversed Mexican Defense, Reti 1.Nf3 d5 2.Nc3
A00 Reversed Nimzovich 1.Nc3 e5   
A00 Reversed Norwegian Defense 1.g3 e5 2.Nf3 e4 3.Nh4
C00 Reversed Philidor, French 1.e4 e6 2.d3 d5 3.Nd2 Nf6 4.Ngf3 Nc6 5.Be2
A00 Reversed Rat 1.d3 e5
A00 Reversed Scaninavian, Dunst 1.Nc3 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qa4
A21 Reversed Sicilian, English; A21 1.c4 e5 2.Nc3
C27 Reversed Spanish, Vienna 1.e4 e5 2.Nc3 Nf6 3.Bc4 Bb4
D48 Reynolds Variation, QGD; D48 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6
D48 Reynolds Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 d5
C39 Rice Gambit Accepted, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.O-O Bxe5
C39 Rice Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.O-O
C52 Richardson Attack, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.O-O Nf6 7.d4 O-O 8.Nxe5
B00 Richter Gambit, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3 dxe4 4.d5 Nb8 5.f3
B01 Richter Variation, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5 4.Nf3 g6
C73 Richter Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.Bxc6+ bxc6 6.d4
C80 Richter Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.d5
D01 Richter Variation, Veresov 1.d4 d5 2.Nc3 Nf6 3.Bg5 Bf5 4.f3
A00 Richter-Grob Gambit 1.g4 d5 2.Bg2 c6 3.c4 dxc4 4.b3
B60 Richter-Rauzer Variation, Sicilian; B60 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5
D01 Richter-Veresov Opening; D01 1.d4 d5 2.Nc3 Nf6 3.Bg5
B00 Riemann Defense, Nimzovich Defense 1.e4 Nc6 2.d4 e5 3.dxe5 Nxe5 4.f4 Nc6
C80 Riga Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 exd4
A01 Ringelbach Gambit, Larsen 1.b3 e5 2.Bb2 f5 3.e4
C67 Rio de Janeiro Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7
C67 Rio Gambit Accepted, Ruy Lopez; C67 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4
D00 Ritter Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 b6 
E16 Riumin Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Bb4+ 6.Bd2 Be7
B20 Rivadavia Gambit, Sicilian 1.e4 c5 2.d4 cxd4 3.c3
C39 Riviere Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.Nxg4 d5
B28 Robatsch Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c4 d6
A13 Romanishin Gambit, English 1.c4 e6 2.Nf3 Nf6 3.g3 a6 4.Bg2 b5
A28 Romanishin Variation, English 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.e3 Bb4 5.Qc2 Bxc3
A15 Romanishin Variation, English 1.c4 Nf6 2.Nf3 e6 3.g3 a6
E20 Romanishin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 c5 5.g3 O-O 6.Bg2
E35 Romanishin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.cxd5 exd5 6.Nf3 Qf5
C95 Romanishin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8 10.d4 Nbd7 11.Nbd2 Bb7 12.Bc2 Re8 13.Nf1 Bf8 14.Bg5
C45 Romanishin Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Bc5 5.Nb3 Bb4+
E23 Romanovsky Gambit, Nimzo-Indian; E23 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3 c5 5.dxc5 Nc6
E25 Romanovsky Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.f3 d5 7.cxd5 Nxd5 8.dxc5 f5
C87 Romanovsky Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 d6 7.c3 O-O 8.d4 Bd7 9.Nbd2 exd4 10.cxd4 Nb4
C68 Romanovsky Variation, Ruy Lopez Exchange 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 bxc6 5.Nc3 f6 6.d3
A00 Romford Counter-Gambit, Grob 1.g4 d5 2.Bg2 Bxg4 3.c4 d4
D46 Romi Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 Bb4
B07 Roscher Gambit, Pirc 1.e4 d6 2.d4 Nf6 3.Nf3
C88 Rosen Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.d4
D21 Rosenthal Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 e6
C67 Rosenthal Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 a6
C46 Rosenthal Variation, Three Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 g6 4.d4 exd4 5.Nd5
C39 Rosenthal; Stockwhip Var, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Qe7
C50 Rosentreter Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d4
C37 Rosentreter Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.d4
C37 Rosentreter-Testa Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.d4 g4 5.Bxf4
C21 Ross Gambit, Center 1.e4 e5 2.d4 exd4 3.Bd3
A04 Ross Gambit, Zukertort 1.Nf3 e5
B30 Rossolimo (Nezmetdinov) Variation, Sicilian; B30 1.e4 c5 2.Nf3 Nc6 3.Bb5
A40 Rossolimo Variation 1.d4 g6 2.c4 Bg7 3.e4 d6 4.Nf3 Bg4
B06 Rossolimo Variation, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nf3 d6 3.c4 Bg4
C60 Rotary-Albany Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 b6
D12 Rotterdam Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5 5.cxd5 cxd5 6.Qb3  
C50 Rousseau Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 f5
E83 Ruban Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 Nc6 7.Nge2 Rb8
D05 Rubinstein Attack, Colle 1.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 c5 5.b3
D64 Rubinstein Attack, Orthodox Defense, QGD;  D64 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6 8.Qc2
C30 Rubinstein Countergambit, KGD 1.e4 e5 2.f4 Bc5 3.Nf3 d6 4.c3 f5
C48 Rubinstein Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Nd4
E10 Rubinstein Variation, Blumenfeld 1.d4 Nf6 2.c4 e6 3.Nf3 c5 4.d5 b5 5.e4
A52 Rubinstein Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Bf4
B13 Rubinstein Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.exd5 cxd3 4.Bd3 Nc6 5.c3 Nf6 6.Bf4
A84 Rubinstein Variation, Dutch 1.d4 f5 2.c4 e6 3.Nc3
C10 Rubinstein Variation, French 1.e4 e6 2.d4 d5 3.Nc3 dxe4
C14 Rubinstein Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7 7.Qd2
C39 Rubinstein Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ne5 Nf6 6.d4
E40 Rubinstein Variation, Nimzo-Indian; E40 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3
E42 Rubinstein Variation, Nimzo-Indian; E42 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Ne2
D61 Rubinstein Variation, Orthodox Defense, QGD; D61 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Qc2
D20 Rubinstein Variation, QGA   1.d4 d5 2.c4 dxc4 3.e4 c5
D27 Rubinstein Variation, QGA; D27 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6
D63 Rubinstein Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 Nbd7 7.Rc1 c6
E16 Rubinstein Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 c5 6.d5 exd5 7.Nh4
A34 Rubinstein Variation, Symmetrical English 1.c4 c5 2.Nc3 Nf6 3.g3 d5 4.cxd5 Nxd5 5.Bg2 Nc7
D45 Rubinstein; anti-Meran 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Ne5
D34 Rubinstein; Normal Position, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O
C02 Ruisdonk Gambit, French 1.e4 e6 2.d4 d5 3.e5 c5 4.Nf3 cxd4 5.Bd3
C79 Russian Defense, Ruy Lopez; C79; Lasker Defense 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O d6
D27 Russian Gambit, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.e4
C42 Russian Three Knights Var, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nc3
D96 Russian Variation, Grunfeld; D96 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3
C60 Ruy Lopez; Spanish Opening; C60 1.e4 e5 2.Nf3 Nc6 3.Bb5
A04 Rydel-Bloodgood Gambit 1.Nf3 f5 2.e4 exf4 3.Ne5
D00 Ryder Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Qxf3
D20 Saduleto Variation, QGA; Central Variation, QGA 1.d4 d5 2.c4 dxc4 3.e4
B02 Saemisch Attack, Alekhine 1.e4 Nf6 2.e5 Nd5 3.Nc3
E51 Saemisch Deferred, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.a3
E80 Saemisch Variation, KID; E80 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3
E24 Saemisch Variation, Nimzo-Indian; E24 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3
E26 Saemisch Variation, Nimzo-Indian; E26 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.e3
D35 Saemisch Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Nf3 Nbd7 6.Bf4
E15 Saemisch Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 c5
D06 Salvio Countergambit, QGD 1.d4 d5 2.c4 c5 3.dxc5 d4
C37 Salvio Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5  
B31 San Francisco Gambit, Sicilian 1.e4 c5 2.Nf3 Nc6 3.Bb5 Na5 4.b4
B00 San Jorge Variation 1.e4 a6 2.d4 b5 3.Nf3 Bb7 4.Bd3 d6 5.O-O g6 6.c3 Bg7
B00 San Jorge Variation 1.e4 a6 2.d4 e6
E37 San Remo Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Ne4 7.Qc2 Nc6 8.e3 e5
E23 San Remo Variation, Nimzo-Indian; Stahlberg Variation 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3 c5 5.dxc5 Nc6 6.Nf3 Ne4 7.Bd2 Nxc5
D41 San Sebastian Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.cxd5 Nxd5 6.e4 Nxc3 7.bxc3 cxd4 8.cxd4 Bb4+ 9.Bd2 Bxd2+
B00 Sanky-Georg Gambit, St George 1.e4 a6 2.d4 e6 3.c4 b5
C37 Santa Maria Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5  Qh4+ 6.Kf1 Nf6
B20 Santasiere Wing Gambit, Sicilian 1.e4 c5 2.b4 cxb4 3.c4
A06 Santasiere's Folly, Reti 1.Nf3 d5 2.b4
E60 Santassiere Variation, KID 1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.b4
A00 Saragossa; Hempel's Opening 1.c3
D00 Sarratt Attack 1.d4 d5 2.Bf4
C37 Sarratt Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6
C60 Sawyer's Gambit, Ruy Lopez; Spanish Countergambit 1.e4 e5 2.Nf3 Nc6 3.Bb5 d5
B20 Scandanavian Formation, Smith-Morra, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 d5
B02 Scandanavian Variation, Alekhine 1.e4 Nf6 2.Nc3 d5
B00 Scandanavian Variation, Nimzovich Defense 1.e4 Nc6 2.d4 d5
C36 Scandinavian Variation, KGA; Modern Defense, KGA; C36 1.e4 e5 2.f4 exf4 3.Nf3 d5
C34 Schallop Defense, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Nf6
D12 Schallopp Defense, Slav; D12 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5
D32 Schara-Hennig; Duisburg Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 cxd4
B80 Scheveingen Variation, Sicilian; B80 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6
B20 Scheveningen Formation, Smith-Morra Accepted 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 e6
B83 Scheveningen Variation, Sicilian; B83 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Be2  
A00 Schiffler-Sokolsky; Tartakower Gambit 1.b4 e5 2.Bb2 f6 3.e4 Bxb4
B01 Schiller-Pytel Variation, Center Counter 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd6 4.d4 c6
C21 Schlechter Defense, Center 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 d5
E52 Schlechter Defense, Nimzo-Indian; E52 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 b6
C80 Schlechter Defense, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.a4 Nxd4
A02 Schlechter Gambit, Bird 1.f4 e5 2.fxe5 Nc6
C01 Schlechter Variation, French 1.e4 e6 2.d4 d5 3.Bd3
D80 Schlechter Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Bd3 c6
D80 Schlechter Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 c6
C41 Schlechter Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Bc4 c6 5.Nc3
B08 Schlechter Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7 5.h3
C86 Schlechter Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Qe2 b5 7.Bb3 O-O 8.c3 d5
D15 Schlechter Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 g6
C46 Schlechter Variation, Three Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Bb4 4.Nd5 Nf6
A43 Schlenker Defense, Benoni 1.d4 c5 2.dxc5 Na6
C70 Schliemann Defense Deferred, Ruy 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 f5
C63 Schliemann; Jaenisch Var, Ruy Lopez; C63 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5
C47 Schmid Gambit, Four Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 exd4 5.Nxd4 Nxe4
B04 Schmid Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.Nf3 Nb6
A43 Schmid Variation, Benoni 1.d4 c5 2.d5 d6 3.Nc3 g6
C44 Schmidt Attack, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 f5 4.d4 d6 5.d5
C45 Schmidt Var; Scotch Four Knights 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.Nc3
A00 Schneider Gambit 1.h4 g5
A47 Schnepper Gambit 1.d4 Nf6 2.Nf3 b6 3.c3 e5
C63 Schoenemann Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.d4
B23 Schofman Variation, Sicilian 1.e4 c5 2.Nc3 Nc6 3.f4 g6 4.Nf3 Bg7 5.Bc4 e6 6.f5
C30 Schubert Variation, KGD 1.e4 e5 2.f4 Qf6 3.Nc3 Qxf4 4.d4
A00 Schuhler Gambit, Polish 1.b4 c6 2.Bb2 a5 3.b5 cxb5 4.e4
C34 Schulder Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 d6 4.b4
C52 Schulen Defense, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4 7.O-O b5
C38 Schultz Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7 5.h4 h6 6.d4 d6 7.Qd3
A10 Schulz Gambit, English 1.c4 d5 2.cxd5 Nf6
C33 Schurig Gambit, KGA 1.e4 e5 2.f4 exf4 3.Bb5
D00 Schuttler Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Nbd7
C15 Schwarz's Line, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.Bd2 Ne7 5.Nb1
C21 Scippler Gambit, Center 1.e4 e5 2.d4 exd4 3.Nf3 Bc5 4.c3 dxc3 5.Bc4
B10 Scorpion-Horus Gambit, Caro-Kann 1.e4 c6 2.Nc3 d5 3.d3 dxe4 4.Bg5
C56 Scotch Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O
C44 Scotch Gambit 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4
C44 Scotch Game 1.e4 e5 2.Nf3 Nc6 3.d4
E00 Seirawan Attack 1.d4 Nf6 2.c4 e6 3.Bg5
B19 Seirawan Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Bf5 5.Ng3 Bg6 6.h4 h6 7.Nf3 Nd7 8.e5 Bh7 9.Bd3 Bxd3 10.Qxd3
E73 Semi-Averbakh System, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Be3
A81 Semi-Leningrad Variation, Dutch 1.d4 f5 2.g3 Nf6 3.Bg2 g6
D31 Semi-Slav Defense 1.d4 d5 2.c4 e6 3.Nc3 c6  
D44 Semi-Slav Defense Accepted; D44 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.Bg5 dxc4
D40 Semi-Tarrasch Variation, QGD; D40 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5
D30 Semmering Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.e3 c6 5.Nbd2 Nbd7 6.Bd3 c5
C30 Senechaud Counter-Gambit, KGD 1.e4 e5 2.f4 Bc5 3.Nf3 g5
C40 Senechaud Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.b4
A80 Seneschaud Gambit, Dutch 1.d4 f5 2.Bf4 e6 3.g4
A40 Seneschaud Variation, Dutch 1.d4 e6 2.Bf4 f5 3.g4
D87 Seville Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 c5 9.O-O Nc6 10.Be3
D45 Shabalov Attack, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Qc2 Bd6 7.g4
C78 Shannon Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Bb7 7.Ng5 d5
C07 Shaposhnikov Gambit, French 1.e4 e6 2.d4 d5 3.Nd2 c5 4.exd5 Nf6
D17 Sharp Line, Wiesbaden Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Ne5 e6 7.f3 Bb4 8.e4
C41 Sharp Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Bc4 Nb6
D00 Shaviliuk Gambit, QP 1.d4 d5 2.Nc3 e5
E42 Sherbakov Attack, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Ne2 cxd4 6.exd4 O-O 7.c5
B89 Sherbakov Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4 Nc6 7.Be3 Be7 8.Bb3 O-O 9.O-O Na5 10.f4 b6
B22 Sherzer Variation, Sicilian 1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.d4 e6 5.Nf3 Nc6
C50 Shilling (Kostic) Gambit, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4
A15 Shirazi Shove 1.c4 Nf6 2.g3 h5
E21 Shocron Gambit, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 c5 5.d5 b5
A00 Short Spike, Grob 1.g4 d5 2.Bg2 c6 3.h3
B12 Short Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.Nf3
D24 Showalter Variation, QGA; D24 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.Nc3
D00 Shropshire Defense 1.d4 d5 2.Nc3 h5 
D00 Siberian Attack 1.d4 d5 2.Qd3 Nc6 3.Nc3
B20 Sicilian Center Game 1.e4 c5 2.d4 cxd4
B20 Sicilian Defense; B20 1.e4 c5 
B27 Sicilian Fred 1.e4 c5 2.Nf3 g6 3.d4 f5
A08 Sicilian Vartiation, KIA; A08 1.Nf3 d5 2.g3 c5
A02 Siegener Gambit, Bird 1.f4 e5 2.d4 exd4 3.Nf3 c5 4.c3
C74 Siesta Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 f5
C37 Silberschmidt Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Ne5  Qh4+ 6.Kf1 Nh6
D97 Simagin (Byrne) Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Nc6
D86 Simagin Improved Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 Nc6
B96 Simagin Line, Najdorf Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 b5 8.e5 dxe5 9.fxe5 Qc7 10.Qe2
E60 Simagin Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 Nc6 7.O-O Bg4
D86 Simagin Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 b6 9.h4 Ba6
E62 Simagin Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nc6 7.O-O Bg4
E46 Simagin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Ne2 d5 6.a3 Bd6
E46 Simagin Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nge2 d5 6.a3 Bd6
C95 Simagin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Nb8 10.d4 Nbd7 11.Nh4
E77 Six Pawns Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6
E76 Six Pawns Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 c5 6.d5 O-O 7.Be2 e6 8.dxe6 fxe6 9.g4 Nc6 10.h4
C80 Skipworth Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.Re1 d5
D11 Slav Bishop's Game 1.d4 d5 2.c4 c6 3.Nf3 Bf5
D10 Slav Defense; Czech Defense, QGD; D10 1.d4 d5 2.c4 c6
D90 Slav Fianchetto 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Nf6 5.Nc3 g6
D21 Slav Gambit, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 b5
D10 Slav Pawn Game 1.d4 d5 2.c4 c6 3.e3
A84 Slav Stonewall, Dutch 1.d4 d5 2.c4 e6 3.Nc3 c6 4.e3 f5
A00 Sleipner Countergambit, Dunst 1.Nc3 d5 2.f4 d4 3.Ne4 e5 4.Nf3
A00 Sleipner Gambit, Dunst 1.Nc3 d5 2.e3 e5 3.d4 Bb4
B20 Slow Sicilian 1.e4 c5 2.Be2
C52 Slow Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.O-O
B07 Small Center Defense 1.e4 d6 2.d4 e6
B06 Small Center Variation, Pirc 1.e4 g6 2.d4 Bg7 3.Nf3 d6 3.Nc3 e6
B00 Smith Gambit, Owen Defense 1.e4 b6 2.d4 Bb7 3.Nf3
B20 Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3
B28 Smith-Morra Line, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d4 cxd4 4.c3
B20 Smith-Morra; Fleissig Gambit, Sic 1.e4 c5 2.d4 cxd4 3.c3
A17 Smyslov Defense, English 1.c4 Nf6 2.Nc3 d5 3.cxd5 Nxd5 4.g3 g6 5.Bg2 Nxc3
B17 Smyslov Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Bc4 Ngf6 6.Ng5 e6 7.Qe2 Nb6
D29 Smyslov Variation, Classical Defense, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O a6 7.Qe2 b5 8.Bb3 Bb7 9.Rd1 Nbd7 10.Nc3 Bd6
A21 Smyslov Variation, English 1.c4 e5 2.Nc3 d6 3.Nf3 Bg4
D80 Smyslov Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Bd3 c6 7.O-O Bg4
D98 Smyslov Variation, Grunfeld; D98 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Bg4
E61 Smyslov Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Bg5
E61 Smyslov Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.Bg5
E48 Smyslov Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.Nf3 c5 7.O-O dxc4 8.Bxc4 Qe7
E55 Smyslov Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Nf3 d5 6.Bd3 c5 7.O-O dxc4 8.Bxc4 Qe7
D25 Smyslov Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 g6
C93 Smyslov Variation, Ruy Lopez; C93 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 h6
D16 Smyslov Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Na6
A05 Smyslov Variation, Zukertort 1.Nf3 Nf6 2.g3 g6 3.b4
B00 Snagkeouss Defense 1.e4 a5 2.d4 Nc6
A43 Snail Variation, Benoni 1.d4 c5 2.d5 Na6
A61 Snake Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 Bd6
D00 Sneiders Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 e5 4.Qh5
B20 Snyder Variation, Sicilian 1.e4 c5 2.b3
C25 Soerensen Defense, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.d4 Qh4+ 5.Ke2 g5
C37 Soerensen Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.d4 Bg4 5.Nc3
E97 Sokolov's Line, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.b4 Nh5 10.Re1
E09 Sokolsky Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2 c6 8.Nbd2 b6 8.Nbd2 b6 9.b3 a5 10.Bb2 Ba6
C52 Sokolsky Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 d6 7.Bg5
D89 Sokolsky Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 c5 9.O-O Nc6 10.Be3 cxd4 11.cxd4 Bg4 12.f3 Na5 13.Bd3 Be6 14.d5
C41 Sokolsky Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.dxe5 Nxe4 5.Nbd2
D00 Soller Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Bf5 4.f3 Nf6 5.Bc4
A40 Soller Gambit Deferred 1.d4 e5 2.dxe5 Nc6 3.Nf3 f6
D00 Soller; Lemberger Var, BDG; Diemer Attack 1.d4 d5 2.e4 dxe4 3.Nc3 e5 4.Be3
A40 Soller; Purchas Gambit 1.d4 e5 2.dxe5 f6
D00 Soller; Vienna Var, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.Bc4
C30 Soller-Zilbermints Gambit, KGD 1.e4 e5 2.f4 f6 3.fxe5 Nc6
D20 Somov Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e4 e5 4.Bxc4
C21 Sorensen Defense, Center 1.e4 e5 2.d4 exd4 3.c3 d5
C37 Sorensen Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.d4 Bg4 5.Ne5
A57 Sosonko Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.a4
B77 Sosonko Variation, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 Nd7
D16 Soultanbeieff Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 e6
C63 Soviet Youth Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 Nd4 5.O-O
B20 Sozin Formation, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 d6 7.O-O a6 8.Qe2 b5
D49 Sozin Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 c5 10.e5 cxd4 11.Nxb5 Nxe5
B57 Sozin; Velimirovic Attack, Sicilian; B57 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bc4
C92 Spanish Benoni, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Qc7 12.d5
E73 Spanish Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5 a6
C48 Spanish Four Knights Game; C48 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5
C44 Spanish Variation, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Bb5
C64 Spanish Wing Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.b4
A40 Spassky Gambit, Polish Defense 1.d4 b5 2.e4 Bb7 3.Bxb5
E14 Spassky System, QID; E14 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.e3
E60 Spassky Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 Nc6 7.O-O Bf5
D87 Spassky Variation, Grunfeld; D87 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 O-O 8.Ne2 c5
D34 Spassky Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Be7 8.O-O O-O 9.Bg5 cxd4 10.Nxd4
A05 Spassky Variation, Zukertort 1.Nf3 Nf6 2.g3 b5
A04 Speelsmet Gambit, Zukertort 1.Nf3 c5 2.d4 cxd4 3.e3
D00 Sperling Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.d5
C24 Spielmann Attack, Bishop 1.e4 e5 2.Bc4 Nf6 3.d3 Bc5 4.Nc3
A32 Spielmann Defense, Symmetrical English; A32 1.c4 c5 2.Nf3 Nf6 3.d4 cxd4 4.Nxd4 e6
A80 Spielmann Gambit, Dutch 1.d4 f5 2.Nc3 Nf6 3.g4
B02 Spielmann Variation, Alekhine 1.e4 Nf6 2.Nc3 d5 3.e5 Nfd7 4.e6
E10 Spielmann Variation, Blumenfeld 1.d4 Nf6 2.c4 e6 3.Nf3 c5 4.d5 b5 5.Bg5 exd5 6.cxd5 h6
C14 Spielmann Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4 O-O
E22 Spielmann Variation, Nimzo-Indian; E22 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3
B56 Spielmann Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Nde2
A46 Spielmann-Indian 1.d4 Nf6 2.Nf3 c5
A00 Spike Deferred 1.g4 g6 2.d3
A00 Spike Deferred; Myers Spike Attack 1.d3 g6 2.g4
A00 Spike Lee Gambit 1.h3 h5 2.g4
A01 Spike Variation, Larsen 1.b3 Nf6 2.Bb2 g6 3.g4
A00 Spike, Grob 1.g4 d5 2.Bg2 c6 3.g5
B00 St George; Birmingham; Baker 1.e4 a6  
A40 St George's Gambit 1.d4 a6 2.c4 b5 3.e4 e6 4.cxb5 axb5
C82 St Petersburg Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5 10.Nbd2
A00 St. George Defense, Dunst 1.Nc3 a6
E43 St. Petersburg Variation, Nimzo-Indian; E43 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 b6
C42 Stafford Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nc6
E23 Stahlberg Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3 c5 5.dxc5 Nc6 6.Nf3 Ne4 7.Bd2 Nxc5 8.Qc2 f5 9.g3
E23 Stahlberg Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qb3 c5 5.dxc5 Nc6 6.Nf3 Ne4 7.Bd2 Nxd2 8.Nxd2 O-O 9.O-O-O
D49 Stahlberg Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.e4 c5 10.e5 cxd4 11.Nxb5 Nxe5 12.Nxe5 axb5
C27 Stanley Variation, Vienna; C27 1.e4 e5 2.Nc3 Nf6 3.Bc4
A43 Staunton Defense; Benoni C-G; A43 1.d4 c5
A82 Staunton Gambit Accepted, Dutch 1.d4 f5 2.e4 fxe4
A82 Staunton Gambit, Dutch; A82 1.d4 f5 2.e4  
C32 Staunton Line, KGD; C32 1.e4 e5 2.f4 d5 3.exd5 e4
C42 Staunton Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Bd6 7.O-O O-O 8.c4 c6
B20 Staunton-Cochrane Variation, Sicilian 1.e4 c5 2.c4  
B10 Stein Attack, Caro-Kann 1.e4 c6 2.d3 d5 3.Nd2 g6 4.g3 Bg7 5.Bg2 e5 6.Ngf3 Ne7 7.O-O O-O 8.b4
A16 Stein Attack, English 1.c4 Nf6 2.Nc3 d5 3.cxd5 Nxd5 4.Nf3 g6 5.Qa4+
E92 Stein Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.d5 a5
C23 Stein Gambit, Bishop 1.e4 e5 2.Bc4 Bc5 3.f4
A00 Steinbok Gambit, Kadas 1.h4 f5 2.e4 fxe4 3.d3
E81 Steiner Attack, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Bg5
A00 Steiner Gambit, Dunst 1.Nc3 d5 2.e4 dxe4 3.Nxe4 e5 4.f4
B28 Steiner Line, Sicilian 1.e4 c5 2.Nf3 a6 3.c3 d6
B02 Steiner Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.c4 Nb6 4.b3
A51 Steiner Variation, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ne4 4.Qc2
E38 Steiner Variation, Nimzo-Indian   1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 c5 5.dxc5 Bxc3+
E20 Steiner Variation, Nimzo-Indian; Romanishin Variation 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.g3
C41 Steiner Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 Nd7 4.Bc4 c6 5.O-O Be7 6.dxe5
C89 Steiner Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d5 9.exd5 e4
D16 Steiner Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bg4
C00 Steinitz Attack, French 1.e4 e6 2.e5
D00 Steinitz Countergambit, Queen Pawn Game 1.d4 d5 2.Bf4 c5
C71 Steinitz Defense Deferred; Ruy Lopez; C71 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6
C62 Steinitz Defense, Ruy Lopez; C62 1.e4 e5 2.Nf3 Nc6 3.Bb5 d6
C46 Steinitz Defense, Three Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 g6
C25 Steinitz Gambit, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.d4
C14 Steinitz Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7 7.f4
C11 Steinitz Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5
C43 Steinitz Variation, Petoff; C43 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.d4
C44 Steinitz Variation, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Qa4 f6
D26 Steinitz Variation, QGA 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.O-O cxd4
C45 Steinitz Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4 5.Nc3
C29 Steinitz Variation, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.d3
C45 Steinitz; Pulling Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Qh4
B20 Steinitz; Tartakower, Lasker-Dunne Variation, Sicilian 1.e4 c5 2.g3
D80 Stockholm Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Bg5
A40 Stockhom Variation, Englund Gambit 1.d4 e5 2.dxe5 Nc6 3.Nf3 Qe7 4.Qd5
B22 Stoltz Attack, Sicilian 1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.Nf3 Nc6 5.Bc4 Nb6 6.Bb3
D45 Stoltz Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Qc2
D00 Stonewall Attack 1.d4 d5 2.e3 Nf6 3.Bd3 c5 4.c3
D00 Stonewall Attack, Queen Pawn Game 1.d4 d5 2.e3 Nf6 3.Bd3
D44 Stonewall Defense, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Ne4 6.Bd3 f5
A84 Stonewall Variation, Dutch 1.d4 f5 2.c4 e6 3.Nc3 Nf6 4.g3 c6 5.Bg2 d5 6.O-O Bd6
C51 Stone-Ware Defense, Evans Gambit 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bd6
C40 Strautins Gambit, Latvian 1.e4 e5 2.Nf3 f5 3.Bc4 b5
D00 Studier Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 g6 6.Bc4 Bg7 7.O-O O-O 8.Qe1
D00 Studier-Rasa Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.Be3
A45 Stummer Gambit 1.d4 Nf6 2.g4 Nxg4 3.e4 d6 4.Be2 Nf6 5.Nc3
A03 Sturm; Mujannah  1.f4 d5 2.c4
C43 Suchting Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 exd4 4.Bc4
D15 Suchting Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 Qb6
C90 Suetin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.a3
C90 Suetin Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 O-O 8.c3 d6 9.a3
C59 Suhle Defense, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6 8.Be2 h6
B06 Suttles Variation, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nc3 d6 4.Nf3 c6
C01 Svenius Variation, French 1.e4 e6 2.d4 d5 3.exd5 exd5 4.Nc3 Nf6 5.Bg5
C21 Svenonius Defense, Center 1.e4 e5 2.d4 exd4 3.c3 Ne7
C49 Svenonius Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 Bxc3 7.bxc3 d5
C10 Svenonius Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.exd5
C30 Svenonius Variation, KGD 1.e4 e5 2.f4 Bc5 3.Nf3 d6 4.Nc3 Nf6 5.Bc4 Nc6 6.d3 Bg4
B33 Sveshnikov Variation, Sicilian 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 9.Bxf6 gxf6 10.Nd5 f5
B07 Sveshnikov-Jansa Attack, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Be3 c6 5.h3
C18 Swiss (Retreat) Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.e5 c5 5.a3 Ba5
B42 Swiss Cheese Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6 5.Bd3 g6
A02 Swiss Gambit, Bird 1.f4 f5 2.e4 fxe4 3.Nc3 Nf6 4.g4
C11 Swiss Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bd3
A46 Swiss; Wagner Gambit 1.d4 Nf6 2.Nf3 e6 3.Bg5 c5 4.e4
A30 Symmetrical Defense, English; A30 1.c4 c5  
D14 Symmetrical Line, Slav; D14 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.cxd5 cxd5 5.Nc3 Nc6 6.Bf4 Bf5
C49 Symmetrical Variation, 4 Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6
A01 Symmetrical Variation, Larsen 1.b3 b6
C43 Symmetrical Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 d5
D02 Symmetrical Variation, QP 1.d4 d5 2.Nf3 Nf6
A36 Symmetrical Variation, Symmetrical English 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7
D32 Symmetrical Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.e3 Nf6 5.Nf3 Nc6
D97 Szabo (Boleslavsky) Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 c6
E60 Szabo Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 Nc6 7.O-O e5
B44 Szen Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nb5
B20 Taimanov Formation, Smith-Morra Accepted, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Bc4 a6 6.Nf3 Ne7
E17 Taimanov Gambit, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.d5 exd5 8.Nd4
B28 Taimanov Line, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d4 cxd4 4.Nxd4 e5
A67 Taimanov Variation, Benoni; A67 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Bg7 8.Bb5
A25 Taimanov Variation, English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7
E40 Taimanov Variation, Nimzo-Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 Nc6
B46 Taimanov Variation, Sicilian 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 a6 6.Be2 Nge7
B44 Taimanov; Bastrikov, Paulsen Variation, Sicilian; B44 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6
C43 Tal Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 exd4 4.e5 Ne4 5.Bb5
B21 Tal Gambit, Sicilian 1.e4 c5 2.f4 d5 3.exd5 Nf6
B12 Tal Variation, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.h4
A60 Tal Variation, Modern Variation, Benoni; A60 1.d4 Nf6 2.c4 c5 3.d5 e6
B82 Tal Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.f4 Nc6 7.Be3 Be7 8.Qf3
A43 Tamarkin Countergambit, Benoni 1.d4 c5 2.Nf3 cxd4 3.b4 e5
B15 Tarrasch (Alekhine) Gambit, Caro 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Bd3
E06 Tarrasch Defense, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 c5 5.Nf3 Nc6
D32 Tarrasch Defense, QGD; D32 1.d4 d5 2.c4 e6 3.Nc3 c5
D32 Tarrasch Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.dxc5 d4 6.Na4 b5
C66 Tarrasch Trap, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O d6 5.d4 Bd7 6.Nc3 Be7 7.Re1 O-O
C14 Tarrasch Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.Bxe7 Qxe7 7.Bd3
C03 Tarrasch Variation, French; C03 1.e4 e6 2.d4 d5 3.Nd2
C42 Tarrasch Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Bd6 7.O-O O-O 8.c4 Bg4
C80 Tarrasch; Open Variation, Ruy Lopez; C80 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4
C52 Tartakower Attack, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 d6 7.Qb3
D08 Tartakower Defense, QGD 1.d4 d5 2.c4 e5 3.dxe5 d4 4.Nf3 c5
D06 Tartakower Gambit, QGD 1.d4 d5 2.c4 Nc6 3.Nc3 e5
C60 Tartakower Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nge7 4.d4 exd4 5.Nxd4 g6 6.Nc3 Bg7 7.Be3 O-O 8.Qd2 d5
B74 Tartakower Line, Sicilian Dragon 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O O-O 9.Nb3 Be6 10.f4 Qc8
B15 Tartakower Variation, Caro 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Nxf6+ exf6
A82 Tartakower Variation, Dutch 1.d4 f5 2.e4 fxe4 3.Nc3 Nf6 4.g4
C12 Tartakower Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.e5 h6 6.Bd2 Nfd7
C14 Tartakower Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Ne4
C50 Tartakower Variation, Hungarian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Be7 4.d4 exd4 5.c3 Nf6 6.e4 Ne4
D58 Tartakower Variation, QGD; D58 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 b6
C80 Tartakower Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.Qe2
C63 Tartakower Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 fxe4 5.Nxe4 Nf6
C45 Tartakower Variation, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.Nxc6 bxc6 6.Nd2
B53 Tartakower Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.c3
A53 Tartakower-Indian 1.d4 Nf6 2.c4 d6 3.Nf3 Bg4
C34 Tashkent Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Nf6 4.e5 Nh5 5.g4
A80 Tate Gambit, Dutch 1.d4 f5 2.g4 fxg4 3.e4 d5 4.Nc3
D00 Tautvaisis Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Qxf3 Nc6
C44 Taylor Opening; Inverted Hungarian 1.e4 e5 2.Nf3 Nc6 3.Be2
D00 Teichmann Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 Bg4
C14 Teichmann Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Nfd7 6.h4 f6
D56 Teichmann Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.e3 O-O 6.Nf3 h6 7.Bh4 Ne4 8.Bxe7 Qxe7 9.Qc2
D00 Tejler Attack, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bf5 5.Bf4
D00 Tejler Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Qxf3 Qxd4 6.Be3 Qg4 7.Qf2 Ne4 8.Nxe4 Qxe4 9.O-O-O Nc6 10.Bd3
A06 Tennison G; Lemberg G; Abonyi G 1.Nf3 d5 2.e4
C54 Therkatz-Herzog, Italian 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.c3 Nf6 5.d4 exd4 6.cxd4 Bb4+ 7.Nc3 Nxe4 8.O-O Bxc3 9.d5 Bf6 10.Re1 Ne7
C39 Thorold Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h6 6.Nxf7 Kxf7 7.d4
C23 Thorold Gambit 1.e4 e5 2.Bc4 b5 3.Bxb5 f5
C46 Three Knights Opening; C46 1.e4 e5 2.Nf3 Nc6 3.Nc3
A27 Three Knights System, English; A27 1.c4 e5 2.Nc3 Nc6 3.Nf3
D90 Three Knights Variation, Grunfeld; D90 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3
E21 Three Knights Variation, Nimzo-Indian; E21 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3
D37 Three Knights Variation, QGD; D37 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3
D15 Three Knights Variation, Slav; D15 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3
C28 Three Knights Variation, Vienna; C28 1.e4 e5 2.Nc3 Nf6 3.Bc4 Nc6
B00 Three Pawn Attack, St George 1.e4 a6 2.d4 e6 3.c4
B06 Three Pawns Attack 1.e4 g6 2.d4 Bg7 3.f4
A40 Thuring Gambit; Hartlaub-Charlick Gambit 1.d4 e5 2.dxe5 d6
B00 Tiers Counter-Gambit 1.e4 f5
E15 Timman's Line, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6 5.Qb3
E18 Tiviakov Defense, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7 6.O-O O-O 7.Nc3 Na6
B17 Tiviakov-Fischer Attack, Caro-Kann 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Bc4 Ngf6 6.Nxf6+ Nxf6
D31 Tolush Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 c6 4.e4 dxe4 5.Nxe4 Bb4+ 6.Bd2 Qxd4 7.Bxb4 Qxe4+8.Be2 c5 9.Bxc5 Qxg2
B01 Tomalty Gambit, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 Nxd5 4.c4 Nf6 5.Nc3 c5
A47 Torre Attack 1.d4 Nf6 2.Nf3 b6 3.Bg5
A46 Torre Attack 1.d4 Nf6 2.Nf3 e6 3.Bg5
D03 Torre Attack, QP; D03 1.d4 d5 2.Nf3 Nf6 3.Bg5
C20 Tortoise Opening 1.e4 e5 2.Bd3
B23 Traditional Closed Sicilian 1.e4 c5 2.Nc3 Nc6
D26 Traditional System QGA; D26 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6
C38 Traditional Variation, KGA; C38 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 Bg7
D30 Traditional Variation, QGD 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Bg5
E17 Traditional Variation, QID; E17 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Be7
C88 Trajkovic Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 Bb7
A40 Transpositional Variation, Keres Defense 1.d4 e6 2.c4 Bb4+ 3.Nc3
C57 Traxler; Wilkes-Barre Var, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Bc5
C57 Trencianske-Teplice Gambit, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Bc5 5.Bxf7+ Ke7 6.d4
C77 Treybel; Flohr; Exchange Var Deferred 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.Bxc6
B03 Trifunovic Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 d6 4.c4 Nb6 5.f4 Bf5
C43 Trifunovic Variation, Petroff 1.e4 e5 2.Nf3 Nf6 3.d4 Nxe4 4.Bd3 d5 5.Nxe5 Bd6 6.O-O O-O 7.c4 Bxe5
C67 Trifunovic Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 d5
D14 Trifunovic Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.cxd5 cxd5 5.Nc3 Nc6 6.Bf4 Bf5 7.e3 e6 8.Qb3 Bb4
A21 Troger Variation, English 1.c4 e5 2.Nc3 d6 3.g3 Be6 4.Bg2 Nc6
A25 Troger Variation, English 1.c4 e5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Be6
A45 Trompowsky; Opocensky; Ruth Opening 1.d4 Nf6 2.Bg5
A00 Tubingen Gambit, Dunst 1.Nc3 Nf6 2.g4
C33 Tumbleweed; King's Own, KGA 1.e4 e5 2.f4 exf4 3.Kf2 
C00 Two Knight Variation, French 1.e4 e6 2.Nc3 d5 3.Nf3
B06 Two Knight Variation, Modern Defense 1.e4 g6 2.d4 Bg7 3.Nc3 d6 4.Nf3
B11 Two Knights Attack, Caro Kann 1.e4 c6 2.Nc3 d5 3.Nf3
D15 Two Knights Attack, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4
C55 Two Knights Defense; C55 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6
A37 Two Knights Line, Symmetrical English; A37 1.c4 c5 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.Nf3
B08 Two Knights System, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Nf3 Bg7  
D01 Two Knights System, Veresov 1.d4 d5 2.Nc3 Nf6 3.Bg5 Nbd7 4.Nf3
B10 Two Knights Variation, Caro 1.e4 c6 2.Nf3 d5 3.Nc3
A31 Two Knights Variation, English 1.c4 c5 2.Nf3 Nf6 3.d4 cxd4 4.Nxd4
A22 Two Knights Variation, English; A22 1.c4 e5 2.Nc3 Nf6
C00 Two Knights Variation, French 1.e4 e6 2.Nf3 d5 3.Nc3
A54 Two Knights Variation, Old Indian; A54 1.d4 Nf6 2.c4 d6 3.Nc3 e5 4.Nf3
A35 Two Knights Variation, Symmetrical English; A35 1.c4 c5 2.Nc3 Nc6   
D32 Two Knights Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3
A00 Twyble Attack, Dunst 1.Nc3 c5 2.Rb1
A45 Ueberlinger Gambit 1.d4 Nf6 2.g3 e5
A61 Uhlmann Variation, Benoni 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.Nf3 g6 7.Bg5
D50 Uhlmann Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7 5.Nf3 h6 6.Bh4 O-O 7.Rc1 dxc4
E62 Uhlmann-Szabo System, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 Nc6 7.O-O e5
E94 Ukranian Defense, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O a5
A53 Ukranian Variation 1.d4 Nf6 2.c4 d6 3.Nc3 e5
D79 Ultra-delayed Exchange Variation, Neo-Grunfeld 1.d4 Nf6 2.c4 g6 3.g3 d5 4.Bg2 Bg7 5.Nf3 O-O 6.O-O c6 7.cxd5 cxd5
C57 Ulvestad Variation, 2 Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 b5
C51 Ulvestad Variation, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Bc5 6.d4 exd4 7.O-O d6 8.cxd4 Bb6 9.d5 Na5 10.Bb2
B12 Ulysses Gambit, Caro 1.e4 c6 2.d4 d5 3.Nf3 dxe4 4.Ng5
B09 Unzicker Attack, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 O-O 6.e5
C42 Urosov Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Bc4
C39 Urusov Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Bc4+ d5 8.Bxd5+ Ke8 9.d4
C43 Urusov Gambit, Petroff 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.d4 exd4 4.Bc4
C24 Urusov; Ouroussoff; Keidansky G 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3
B12 Van der Wiel Attack, Caro-Kann 1.e4 c6 2.d4 d5 3.e5 Bf5 4.Nc3
A50 Van Geet; Kevitz; Trajkovic; Mexican 1.d4 Nf6 2.c4 Nc6
A00 Van Kruijk Gambit 1.g3 h5 2.Nf3 h4
A00 Van't Kruijs Opening 1.e3 e5
B00 Vehre Variation, Nimzovich Defense 1.e4 Nc6 2.d4 d5 3.Nc3 Nf6
B89 Velimirovic Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bc4 Nc6 7.Be3 Be7 8.Qe2
A00 Venezolana 1.d3 c5 2.Nc3 Nc6 3.g3
B55 Venice Attack, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.f3 e5 6.Bb5+
B56 Venice Attack, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Bb5+
B28 Venice System, Sicilian 1.e4 c5 2.Nf3 a6 3.c3
D01 Veresov Variation, QP 1.d4 d5 2.Nc3 Nf6 3.Bg5 Bf5 4.Bxf6
D20 Versov; Betbeder; Schwartz Defense, QGA 1.d4 d5 2.c4 dxc4 3.e4 f5
C25 Vienna Gambit 1.e4 e5 2.Nc3 Nc6 3.f4
C29 Vienna Gambit, Vienna; C29 1.e4 e5 2.Nc3 Nf6 3.f4
C24 Vienna Hybrid, Bishop 1.e4 e5 2.Bc4 Nf6 3.d3 Nc6 4.Nc3
D00 Vienna Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6
D80 Vienna Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.e3 Bg7 5.Nf3 O-O 6.Qb3
D30 Vienna Variation, QGD   1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.Bg5 Bb4+
D39 Vienna Variation, QGD; D39 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 Bb4 5.Bg5 dxc4
D44 Vienna Variation, Semi-Slav 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 dxc4
C25 Vienna; Hamppe Opening; C25 1.e4 e5 2.Nc3  
B23 Vinken System, Sicilian; Grand Prix Attack 1.e4 c5 2.Nc3 Nc6 3.f4
C60 Vinogradov Var, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Qe7
C13 Vistaneckis (Nimzovich) Variation, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Be7 5.e5 Ng8
B80 Vitolins Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e6 6.Bb5+
E33 Vitolinsh-Adorjan Gambit, Nimzo Indian 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 O-O 5.a3 Bxc3+ 6.Qxc3 b5
C44 Vitzhum Attack, Scotch 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Bc5 5.Ng5 Nh6 6.Qh5
A45 Von Beivorseen 1.d4 Nf6 2.Nc3 c5 3.dxc5
C21 Von der Lasa Gambit 1.e4 e5 2.d4 exd4 3.Bc4
B15 Von Hennig Gambit, Caro 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Bc4
D32 Von Hennig Gambit, QGD 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 cxd4 5.Qxd4 Nc6 6.Qd1 exd5 7.Qxd5 Be6
D00 Von Popiel Gambit 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.Bg5
A04 Vos Gambit, Zukertort 1.Nf3 d6 2.d4 e5
C44 Vukovic Gambit, Ponziani 1.e4 e5 2.Nf3 Nc6 3.c3 Nf6 4.d4 Nxe4 5.d5 Bc5
A56 Vulture Defense, Benoni 1.d4 c5 2.d5 Nf6 3.c4 Ne4
A56 Vulture Variation; Der Geier 1.d4 Nf6 2.c4 c5 3.d5 Ne4
A41 Wade Defense 1.d4 d6 2.Nf3 Bg4
A04 Wade Defense 1.Nf3 d6
A10 Wade Gambit, English 1.c4 f5 2.g4
C02 Wade Variation, French 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Qb6 5.Nf3 Bd7
D47 Wade Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4 b5 8.Bd3 Bb7
A04 Wade-Tartakower Defense, Zukertort 1.Nf3 d6 2.e4 Bg4
D33 Wagner Variation, Tarrasch 1.d4 d5 2.c4 e6 3.Nc3 c5 4.cxd5 exd5 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 Bg4
A02 Wagner-Zwitersch Gambit, Bird 1.f4 f5 2.e4
C39 Walker (Urusov) Attack, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Bc4+
C23 Walker Variation, Bishop 1.e4 e5 2.Bc4 Bc5 3.c3 d5 4.Bxd5 Nf6 5.d4
C20 Walkerling 1.e4 e5 2.f3 Nf6  
B03 Wall Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.d4 c5
B20 Wall Variation, Sicilian 1.e4 c5 2.d4 Nf6 3.e5 Nd5
C52 Waller Attack, Evans 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4 7.O-O d6 8.Qb3
B00 Ware Defense 1.e4 a5
A00 Ware Gambit 1.a4 e5 2.a5 d5 3.e3 f5 4.a6
A00 Ware; Meadow Hay; Crab 1.a4
C24 Warsaw Gambit, Bishop 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.c3
A88 Warsaw Variation, Dutch; A88 1.d4 f5 2.c4 Nf6 3.g3 g6 4.Bg2 Bg7 5.Nf3 O-O 6.O-O d6 7.Nc3 c6
A00 Warsteiner Gambit, Dunst 1.Nc3 d5 2.f4 g5
C40 Wasp Variation 1.e4 e5 2.Nf3 d5 3.Nxe5 dxe4 4.Bc4 Qg5
C20 Wayward Queen; Danvers; Parnham 1.e4 e5 2.Qh5
C20 Weber Gambit 1.e4 e5 2.d3 d5 3.exd5 c6 4.dxc6 Nxc6
A45 Webster Gambit 1.d4 Nf6 2.f3 c5 3.d5 e6 4.e4 exd5 5.e5
A56 Weenink Variation, Benoni 1.d4 Nf6 2.c4 c5 3.dxc5 e6
D00 Weinsbach Declination, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 e6
C33 Weiss Defense, KGA 1.e4 e5 2.f4 exf4 3.Be2 f5 4.exf5 d6
B09 Weiss Variation, Pirc 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 O-O 6.Bd3
B02 Welling Variation, Alekhine 1.e4 Nf6 2.e5 Nd5 3.b3
D00 Welling Variation, Queen Pawn Game 1.d4 d5 2.Bg5 Bg4
C67 Westerinen Line, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Ne4
B06 Westermann Gambit 1.e4 g6 2.d4 Bg7 3.Bd2
D51 Westphalian Variation, QGD 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Nbd7 5.e3 Bb4 6.Nf3 c5
C20 Whale Opening 1.e4 e5 2.c4
B00 Wheeler Gambit, Nimzovich Defense 1.e4 Nc6 2.b4 Nxb4 3.c3 Nc6 4.d4
A00 Wiedenhagen-Beta Gambit 1.g3 d5 2.Nf3 g5
D17 Wiesbaden Variation, Slav 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.a4 Bf5 6.Ne5 e6
D00 Wiesengren Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 Bc5
A52 Wikstrom Gambit, Budapest 1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.e4 Nxe5 5.f4 Nbc6
B00 Wild Bull Defense 1.e4 Nh6
C35 Wild Cunningham Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 Be7 4.Bc4 Bh4+  
A03 Williams Gambit, Bird 1.f4 d5 2.e4 dxe4 3.Nc3
B00 Williams Variation, Nimzovich 1.e4 Nc6 2.Nf3 d6
A13 Wimpy System, English 1.c4 e6 2.Nf3 d5 3.b3 Nf6 4.Bb2 c5 e3
C67 Winawer Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 Nd6 7.Bxc6+ bxc6 8.dxe5 Nb7 9.Nd4 O-O
D10 Winawer Counter Gambit, Slav 1.d4 d5 2.c4 c6 3.Nc3 e5
C46 Winawer Defense, Three Knights 1.e4 e5 2.Nf3 Nc6 3.Nc3 f5
C15 Winawer Variation, French; C15 1.e4 e6 2.d4 d5 3.Nc3 Bb4  
C15 Winckelmann-Riemer Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 Bb4 4.a3
B06 Wind Gambit 1.e4 g6 2.d4 Bg7 3.Bd3
B00 Wind Gambit, Owen Defense 1.e4 b6 2.d4 Bb7 3.f3 e5
C78 Wing Attack, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Be7 7.a4
B20 Wing Formation, Smith-Morra Declined, Sicilian 1.e4 c5 2.d4 cxd4 3.c3 Qa5
B51 Wing Gambit Deferred, Sicilian 1.e4 c5 2.Nf3 d6 3.b4
B40 Wing Gambit Deferred, Sicilian 1.e4 c5 2.Nf3 e6 3.b4
B01 Wing Gambit, Center Counter 1.e4 d5 2.exd5 Nf6 3.d4 g6 4.c4 b5
C00 Wing Gambit, French 1.e4 e6 2.Nf3 d5 3.e5 c5 4.b4
B20 Wing Gambit, Sicilian 1.e4 c5 2.b4
B28 Wing Gambit, Sicilian 1.e4 c5 2.Nf3 a6 3.b4
A00 Wing Gambit, Ware Opening 1.a4 b5
A30 Wing Variation, English 1.c4 c5 2.b4
B20 Wing; Carlsbad Variation, Sicilian 1.e4 c5 2.b4 cxb4 3.a3 bxa3
A00 Winterberg Gambit 1.g3 d5 2.Bg2 e5 3.c4 dxc4 4.b3
C12 Wolf Gambit, French 1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.Bg5 Bb4 5.Nge2
A00 Wolferts Gambit, Polish 1.b4 e5 2.Bb2 c5
B00 Woodchuck Variation, St George 1.e4 a6 2.d4 Nc6
A43 Woozle Defense, Benoni 1.d4 c5 2.d5 Nf6 3.Nc3 Qa5
C77 Wormald Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.Qe2
C86 Worrall Attack, Ruy Lopez; C86 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Qe2
A00 Wulumulu 1.h4 e5 2.d4
C29 Wurzburger Trap, Vienna 1.e4 e5 2.Nc3 Nf6 3.f4 d5 4.fxe5 Nxe4 5.d3 Qh4 6.g3 Nxg3 7.Nf3 Qh5 8.Nd5 Bxd5 9.Nf4
C58 Yankovich Variation, Two Knights 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.d3 h6 7.Nf3 e4 8.Qe2 Nxc4 9.dxc4 Bc5 10.Nfd2
E83 Yates Defense, KID; E83 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 O-O 6.Be3 Nc6
E16 Yates Variation, QID 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Bb7 5.Bg2 Bb4+ 6.Bd2 a5
C91 Yates Variation, Ruy; C91 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.d4
B56 Yates Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bd3
D20 Yefimov Gambit, QGA 1.d4 d5 2.c4 dxc4 3.e4 c5 4.d5 b5
E97 Yepishin's Line, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7 9.b4 Nh5 10.Qc2
B28 Yerevan System, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.Nc3
C37 Young Gambit, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qf6 7.Bxf7+ Kxf7 8.d4 Qxd4+ 9.Be3 Qf6
C37 Young Variation, KGA 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.Bxf7+ Kxf7 6.O-O gxf3 7.Qxf3 Qf6 8.d4 Qxd4+ 9.Be3
B76 Yugoslav Attack, Sicilian Dragon; B76 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O
E60 Yugoslav Variation 1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d6 5.Nf3 O-O 6.Nc3 c5
D99 Yugoslav Variation, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 O-O 7.e4 Bg4 8.Be3 Nfd7 9.Qb3 c5
E64 Yugoslav Variation, KID; E64 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.Nf3 d6 5.g3 O-O 6.Bg2 c5
A46 Yusupov-Rubinstein System 1.d4 Nf6 2.Nf3 e6 3.e3
E08 Zagoriansky Variation, Catalan 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2 c6 8.Rd1 b6 9.a4
B28 Zagorovsky Line, O'Kelly Sicilian 1.e4 c5 2.Nf3 a6 3.d4 cxd4 4.Qxd4
B91 Zagreb Variation, Sicilian; B91 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.g3
A40 Zaire Defense 1.d4 Nc6 2.d5 Nb8 3.e4 Nf6 5.e5 Ng8
D80 Zaitsev Gambit, Grunfeld 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.h4
A57 Zaitsev System, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.Nc3  
C92 Zaitsev System, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Re8
A57 Zaitsev Variation, Benko Gambit 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.Nc3 axb5 6.e4 b4 7.Nb5 d6 8.Nf3 g6 9.Bc4
C64 Zaitsev Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.O-O Nd4 5.b4
B53 Zaitsev Variation, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Qxd4 Nc6 5.Bb5 Qd7
D00 Zeller Defesne, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Bf5
D00 Zeller Defesne, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Bf5 4.f3 exf3 5.Qxf3 Bc8
C25 Zhuraviev Countergambit, Vienna 1.e4 e5 2.Nc3 Bb4 3.Qg4 Nf6
C25 Zhuravlev Counter-Gambit, Vienna 1.e4 e5 2.Nc3 Bb4 3.Qg4
D00 Ziegler; Gunderam's 2nd Defense, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 c6
C30 Zilbermints Double Countergambit; KGD 1.e4 e5 2.f4 g5
C30 Zilbermints Double Gambit I, KGD 1.e4 e5 2.f4 Nc6 3.Nf3 g5
A40 Zilbermints Gambit 1.d4 e6 2.c4 e5
A40 Zilbermints Gambit II, Englund Gambit 1.d4 e5 2.dxe5 Nc6 3.Nf3 h6
D00 Zilbermints Gambit, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6  6.Bg5 Be7 7.Bd3 Nc6 8.O-O Nxd4 9.Kh1
B00 Zilbermints Gambit, Borg 1.e4 g5 2.d4 e5
B00 Zilbermints Gambit, Carr Defense 1.e4 h6 2.d4 e5
B01 Zilbermints Gambit, Center Counter 1.e4 d5 2.b4
A10 Zilbermints Gambit, English 1.c4 g5 2.d4 e5
A40 Zilbermints Gambit, Englund Gambit 1.d4 e5 2.dxe5 Nc6 3.Nf3 Nge7
A00 Zilbermints Gambit, Grob 1.g4 d5 2.e4
A00 Zilbermints Gambit, Grob 1.g4 d5 2.e4 dxe4 3.Nc3
D06 Zilbermints Gambit, QGD 1.d4 d5 2.c4 b5
A09 Zilbermints Gambit, Reti 1.Nf3 d5 2.c4 b5
B00 Zilbermints Gambit, St George Defense 1.e4 a6 2.d4 e5
A43 Zilbermints Gambit; Nakamura Gambit, Benoni 1.d4 c5 2.b4 cxb4
D00 Zilbermints Variation, BDG 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.Bg5 Bf5 5.Bxf6 exf6 6.g4 Bg6 7.Qe2 Bb4 8.Qb5+
D02 Zilbermints Variation, QP 1.d4 d5 2.Nf3 Nf6 3.c4 b5
A43 Zilbermints-Benoni Gambit 1.d4 c5 2.Nf3 cxd4 3.b4
E90 Zinnowitz Variation, KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Bg5
B73 Zollner Gambit, Sicilian 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Be2 Nc6 8.O-O O-O 9.f4 Qb6
D00 Zot 1.d4 d5 2.Bg5
C25 Zukertort Defense, Vienna 1.e4 e5 2.Nc3 Nc6 3.f4 exf4 4.d4 Qh4+ 5.Ke2 d5
C64 Zukertort Gambit, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.O-O Nf6 5.c3
C41 Zukertort Variation, Philidor 1.e4 e5 2.Nf3 d6 3.d4 f5 4.Nc3
D05 Zukertort Variation, QP 1.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3
D02 Zukertort Variation, QP; D02 1.d4 d5 2.Nf3
C80 Zukertort Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Ne7
C67 Zukertort Variation, Ruy Lopez 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Nxe4 5.d4 Be7 6.Qe2 Nd6 7.Bxc6+ bxc6 8.dxe5 Nb7 9.c4
D00 Zurich Gambit 1.d4 d5 2.g4
A17 Zviagintsev-Krasenkov Attack, English 1.c4 Nf6 2.Nc3 e6 3.Nf3 Bb4 4.g4