ECO codes · A00–E99
The ECO system files every chess opening under one of 500 codes in five volumes. Here are all of them with the 3,690 named lines behind them — or browse the openings A–Z.
A · Flank Openings A00–A99
- A00 Van Geet Opening, Polish Opening & more 143 lines
- A01 Nimzo-Larsen Attack 15 lines
- A02 Bird Opening 19 lines
- A03 Bird Opening 8 lines
- A04 Zukertort Opening, Modern Defense & more 31 lines
- A05 Zukertort Opening, King's Indian Attack & more 13 lines
- A06 Zukertort Opening & Nimzo-Larsen Attack 13 lines
- A07 King's Indian Attack & Hungarian Opening 17 lines
- A08 King's Indian Attack & Zukertort Opening 8 lines
- A09 Réti Opening 9 lines
- A10 English Opening 20 lines
- A11 Réti Opening & English Opening 12 lines
- A12 Réti Opening 11 lines
- A13 English Opening 16 lines
- A14 English Opening & Réti Opening 12 lines
- A15 English Opening & English Orangutan 15 lines
- A16 English Opening 7 lines
- A17 English Opening 6 lines
- A18 English Opening 3 lines
- A19 English Opening 2 lines
- A20 English Opening 5 lines
- A21 English Opening 6 lines
- A22 English Opening 8 lines
- A23 English Opening 2 lines
- A24 English Opening 1 line
- A25 English Opening 7 lines
- A26 English Opening 2 lines
- A27 English Opening 1 line
- A28 English Opening 9 lines
- A29 English Opening 12 lines
- A30 English Opening 6 lines
- A31 English Opening 1 line
- A32 English Opening 1 line
- A33 English Opening 2 lines
- A34 English Opening 6 lines
- A35 English Opening 3 lines
- A36 English Opening 4 lines
- A37 English Opening 7 lines
- A38 English Opening 3 lines
- A39 English Opening 1 line
- A40 Englund Gambit, English Defense & more 52 lines
- A41 Rat Defense, Modern Defense & more 10 lines
- A42 Modern Defense & Pterodactyl Defense 6 lines
- A43 Benoni Defense, Queen's Pawn Game & more 20 lines
- A44 Benoni Defense 2 lines
- A45 Indian Defense, Trompowsky Attack & more 31 lines
- A46 Indian Defense, Torre Attack & more 15 lines
- A47 Pseudo Queen's Indian Defense, Marienbad System & more 5 lines
- A48 London System, Queen's Pawn Game & more 16 lines
- A49 Indian Defense 1 line
- A50 Indian Defense, Mexican Defense & more 7 lines
- A51 Indian Defense 4 lines
- A52 Indian Defense 6 lines
- A53 Old Indian Defense 8 lines
- A54 Old Indian Defense 4 lines
- A55 Old Indian Defense 1 line
- A56 Benoni Defense, Vulture Defense & more 7 lines
- A57 Benko Gambit Declined, Benko Gambit & more 15 lines
- A58 Benko Gambit Accepted & Benko Gambit 5 lines
- A59 Benko Gambit Accepted & Benko Gambit 4 lines
- A60 Benoni Defense 2 lines
- A61 Benoni Defense 4 lines
- A62 Benoni Defense 1 line
- A63 Benoni Defense 1 line
- A64 Benoni Defense 1 line
- A65 Benoni Defense 9 lines
- A66 Benoni Defense 2 lines
- A67 Benoni Defense 1 line
- A68 Benoni Defense 1 line
- A69 Benoni Defense 1 line
- A70 Benoni Defense 3 lines
- A71 Benoni Defense 1 line
- A72 Benoni Defense 1 line
- A73 Benoni Defense 1 line
- A74 Benoni Defense 1 line
- A75 Benoni Defense 1 line
- A76 Benoni Defense 1 line
- A77 Benoni Defense 1 line
- A78 Benoni Defense 1 line
- A79 Benoni Defense 1 line
- A80 Dutch Defense & Queen's Pawn Game 18 lines
- A81 Dutch Defense 5 lines
- A82 Dutch Defense & Rat Defense 6 lines
- A83 Dutch Defense 5 lines
- A84 Dutch Defense 7 lines
- A85 Dutch Defense 1 line
- A86 Dutch Defense 3 lines
- A87 Dutch Defense 1 line
- A88 Dutch Defense 1 line
- A89 Dutch Defense 1 line
- A90 Dutch Defense 5 lines
- A91 Dutch Defense 2 lines
- A92 Dutch Defense 4 lines
- A93 Dutch Defense 1 line
- A94 Dutch Defense 1 line
- A95 Dutch Defense 2 lines
- A96 Dutch Defense 3 lines
- A97 Dutch Defense 2 lines
- A98 Dutch Defense 1 line
- A99 Dutch Defense 1 line
B · Semi-Open Games B00–B99
- B00 Nimzowitsch Defense, Owen Defense & more 83 lines
- B01 Scandinavian Defense & Van Geet Opening 46 lines
- B02 Alekhine Defense 27 lines
- B03 Alekhine Defense 18 lines
- B04 Alekhine Defense 6 lines
- B05 Alekhine Defense 5 lines
- B06 Modern Defense, Pterodactyl Defense & more 46 lines
- B07 Pirc Defense, Lion Defense & more 17 lines
- B08 Pirc Defense 7 lines
- B09 Pirc Defense 8 lines
- B10 Caro-Kann Defense 28 lines
- B11 Caro-Kann Defense 3 lines
- B12 Caro-Kann Defense 24 lines
- B13 Caro-Kann Defense 15 lines
- B14 Caro-Kann Defense 4 lines
- B15 Caro-Kann Defense 13 lines
- B16 Caro-Kann Defense 2 lines
- B17 Caro-Kann Defense 8 lines
- B18 Caro-Kann Defense 5 lines
- B19 Caro-Kann Defense 4 lines
- B20 Sicilian Defense 27 lines
- B21 Sicilian Defense & Bird Opening 34 lines
- B22 Sicilian Defense 12 lines
- B23 Sicilian Defense 11 lines
- B24 Sicilian Defense 4 lines
- B25 Sicilian Defense 5 lines
- B26 Sicilian Defense 1 line
- B27 Sicilian Defense, Pterodactyl Defense & more 23 lines
- B28 Sicilian Defense 20 lines
- B29 Sicilian Defense 5 lines
- B30 Sicilian Defense 9 lines
- B31 Sicilian Defense 5 lines
- B32 Sicilian Defense 11 lines
- B33 Sicilian Defense 11 lines
- B34 Sicilian Defense 2 lines
- B35 Sicilian Defense 2 lines
- B36 Sicilian Defense 2 lines
- B37 Sicilian Defense 2 lines
- B38 Sicilian Defense 1 line
- B39 Sicilian Defense 1 line
- B40 Sicilian Defense 18 lines
- B41 Sicilian Defense 5 lines
- B42 Sicilian Defense 4 lines
- B43 Sicilian Defense 4 lines
- B44 Sicilian Defense 4 lines
- B45 Sicilian Defense 6 lines
- B46 Sicilian Defense 1 line
- B47 Sicilian Defense 2 lines
- B48 Sicilian Defense 1 line
- B49 Sicilian Defense 1 line
- B50 Sicilian Defense 12 lines
- B51 Sicilian Defense 3 lines
- B52 Sicilian Defense 3 lines
- B53 Sicilian Defense 2 lines
- B54 Sicilian Defense 4 lines
- B55 Sicilian Defense 1 line
- B56 Sicilian Defense 6 lines
- B57 Sicilian Defense 3 lines
- B58 Sicilian Defense 4 lines
- B59 Sicilian Defense 1 line
- B60 Sicilian Defense 3 lines
- B61 Sicilian Defense 1 line
- B62 Sicilian Defense 5 lines
- B63 Sicilian Defense 4 lines
- B64 Sicilian Defense 2 lines
- B65 Sicilian Defense 2 lines
- B66 Sicilian Defense 1 line
- B67 Sicilian Defense 1 line
- B68 Sicilian Defense 1 line
- B69 Sicilian Defense 1 line
- B70 Sicilian Defense 3 lines
- B71 Sicilian Defense 2 lines
- B72 Sicilian Defense 6 lines
- B73 Sicilian Defense 3 lines
- B74 Sicilian Defense 7 lines
- B75 Sicilian Defense 3 lines
- B76 Sicilian Defense 4 lines
- B77 Sicilian Defense 6 lines
- B78 Sicilian Defense 4 lines
- B79 Sicilian Defense 2 lines
- B80 Sicilian Defense 4 lines
- B81 Sicilian Defense 1 line
- B82 Sicilian Defense 2 lines
- B83 Sicilian Defense 4 lines
- B84 Sicilian Defense 3 lines
- B85 Sicilian Defense 4 lines
- B86 Sicilian Defense 1 line
- B87 Sicilian Defense 1 line
- B88 Sicilian Defense 2 lines
- B89 Sicilian Defense 3 lines
- B90 Sicilian Defense 10 lines
- B91 Sicilian Defense 1 line
- B92 Sicilian Defense 4 lines
- B93 Sicilian Defense 1 line
- B94 Sicilian Defense 2 lines
- B95 Sicilian Defense 1 line
- B96 Sicilian Defense 4 lines
- B97 Sicilian Defense 2 lines
- B98 Sicilian Defense 4 lines
- B99 Sicilian Defense 1 line
C · Open Games C00–C99
- C00 French Defense & Rat Defense 43 lines
- C01 French Defense 6 lines
- C02 French Defense 22 lines
- C03 French Defense 6 lines
- C04 French Defense 1 line
- C05 French Defense 4 lines
- C06 French Defense 2 lines
- C07 French Defense 7 lines
- C08 French Defense 2 lines
- C09 French Defense 1 line
- C10 French Defense 10 lines
- C11 French Defense 19 lines
- C12 French Defense 13 lines
- C13 French Defense 13 lines
- C14 French Defense 8 lines
- C15 French Defense 14 lines
- C16 French Defense 2 lines
- C17 French Defense 9 lines
- C18 French Defense 16 lines
- C19 French Defense 14 lines
- C20 King's Pawn Game, King's Pawn Opening & more 30 lines
- C21 Center Game, Danish Gambit Accepted & more 19 lines
- C22 Center Game 7 lines
- C23 Bishop's Opening 24 lines
- C24 Bishop's Opening 10 lines
- C25 Vienna Game & Vienna Gambit 31 lines
- C26 Vienna Game & Bishop's Opening 10 lines
- C27 Vienna Game & Bishop's Opening 7 lines
- C28 Vienna Game & Bishop's Opening 3 lines
- C29 Vienna Game 10 lines
- C30 King's Gambit Declined & King's Gambit 32 lines
- C31 King's Gambit Declined & Van Geet Opening 15 lines
- C32 King's Gambit Declined 8 lines
- C33 King's Gambit Accepted 46 lines
- C34 King's Gambit Accepted 13 lines
- C35 King's Gambit Accepted 4 lines
- C36 King's Gambit Accepted 4 lines
- C37 King's Gambit Accepted 34 lines
- C38 King's Gambit Accepted 6 lines
- C39 King's Gambit Accepted 30 lines
- C40 Latvian Gambit, King's Pawn Game & more 40 lines
- C41 Philidor Defense 44 lines
- C42 Petrov's Defense 38 lines
- C43 Petrov's Defense & Bishop's Opening 12 lines
- C44 Scotch Game, Ponziani Opening & more 53 lines
- C45 Scotch Game 28 lines
- C46 Three Knights Opening 6 lines
- C47 Four Knights Game 19 lines
- C48 Four Knights Game 13 lines
- C49 Four Knights Game 15 lines
- C50 Italian Game & Four Knights Game 20 lines
- C51 Italian Game 29 lines
- C52 Italian Game 22 lines
- C53 Italian Game 8 lines
- C54 Italian Game 43 lines
- C55 Italian Game 5 lines
- C56 Italian Game 24 lines
- C57 Italian Game 17 lines
- C58 Italian Game 10 lines
- C59 Italian Game 4 lines
- C60 Ruy Lopez 19 lines
- C61 Ruy Lopez 2 lines
- C62 Ruy Lopez 5 lines
- C63 Ruy Lopez 9 lines
- C64 Ruy Lopez 10 lines
- C65 Ruy Lopez 13 lines
- C66 Ruy Lopez 7 lines
- C67 Ruy Lopez 16 lines
- C68 Ruy Lopez 6 lines
- C69 Ruy Lopez 5 lines
- C70 Ruy Lopez 12 lines
- C71 Ruy Lopez 4 lines
- C72 Ruy Lopez 2 lines
- C73 Ruy Lopez 2 lines
- C74 Ruy Lopez 3 lines
- C75 Ruy Lopez 2 lines
- C76 Ruy Lopez 1 line
- C77 Ruy Lopez 8 lines
- C78 Ruy Lopez 8 lines
- C79 Ruy Lopez 4 lines
- C80 Ruy Lopez 18 lines
- C81 Ruy Lopez 3 lines
- C82 Ruy Lopez 7 lines
- C83 Ruy Lopez 6 lines
- C84 Ruy Lopez 6 lines
- C85 Ruy Lopez 1 line
- C86 Ruy Lopez 4 lines
- C87 Ruy Lopez 1 line
- C88 Ruy Lopez 9 lines
- C89 Ruy Lopez 8 lines
- C90 Ruy Lopez 4 lines
- C91 Ruy Lopez 3 lines
- C92 Ruy Lopez 6 lines
- C93 Ruy Lopez 1 line
- C94 Ruy Lopez 2 lines
- C95 Ruy Lopez 4 lines
- C96 Ruy Lopez 6 lines
- C97 Ruy Lopez 3 lines
- C98 Ruy Lopez 2 lines
- C99 Ruy Lopez 1 line
D · Closed & Semi-Closed Games D00–D99
- D00 Queen's Pawn Game, Blackmar-Diemer Gambit Accepted & more 70 lines
- D01 Richter-Veresov Attack & Rapport-Jobava System 12 lines
- D02 Queen's Pawn Game, Queen's Gambit Declined & more 14 lines
- D03 Queen's Pawn Game 3 lines
- D04 Queen's Pawn Game 3 lines
- D05 Rubinstein Opening & Queen's Pawn Game 11 lines
- D06 Queen's Gambit Declined & Queen's Gambit 13 lines
- D07 Queen's Gambit Declined 11 lines
- D08 Queen's Gambit Declined 9 lines
- D09 Queen's Gambit Declined 4 lines
- D10 Slav Defense 9 lines
- D11 Slav Defense 6 lines
- D12 Slav Defense 4 lines
- D13 Slav Defense 2 lines
- D14 Slav Defense 2 lines
- D15 Slav Defense 10 lines
- D16 Slav Defense 4 lines
- D17 Slav Defense 8 lines
- D18 Slav Defense 2 lines
- D19 Slav Defense 3 lines
- D20 Queen's Gambit Accepted 17 lines
- D21 Queen's Gambit Accepted 6 lines
- D22 Queen's Gambit Accepted 3 lines
- D23 Queen's Gambit Accepted 2 lines
- D24 Queen's Gambit Accepted 4 lines
- D25 Queen's Gambit Accepted 4 lines
- D26 Queen's Gambit Accepted 6 lines
- D27 Queen's Gambit Accepted 4 lines
- D28 Queen's Gambit Accepted 3 lines
- D29 Queen's Gambit Accepted 2 lines
- D30 Queen's Gambit Declined & Semi-Slav Defense 12 lines
- D31 Semi-Slav Defense & Queen's Gambit Declined 20 lines
- D32 Tarrasch Defense & Queen's Gambit Declined 9 lines
- D33 Tarrasch Defense 6 lines
- D34 Tarrasch Defense & Queen's Gambit Declined 13 lines
- D35 Queen's Gambit Declined 9 lines
- D36 Queen's Gambit Declined 4 lines
- D37 Queen's Gambit Declined 14 lines
- D38 Queen's Gambit Declined 3 lines
- D39 Queen's Gambit Declined 1 line
- D40 Queen's Gambit Declined 4 lines
- D41 Queen's Gambit Declined 8 lines
- D42 Queen's Gambit Declined 1 line
- D43 Semi-Slav Defense 4 lines
- D44 Semi-Slav Defense & Semi-Slav Defense Accepted 7 lines
- D45 Semi-Slav Defense 15 lines
- D46 Semi-Slav Defense 12 lines
- D47 Semi-Slav Defense 6 lines
- D48 Semi-Slav Defense 5 lines
- D49 Semi-Slav Defense 6 lines
- D50 Queen's Gambit Declined 6 lines
- D51 Queen's Gambit Declined 7 lines
- D52 Queen's Gambit Declined 8 lines
- D53 Queen's Gambit Declined 5 lines
- D54 Queen's Gambit Declined 1 line
- D55 Queen's Gambit Declined 6 lines
- D56 Queen's Gambit Declined 3 lines
- D57 Queen's Gambit Declined 3 lines
- D58 Queen's Gambit Declined 2 lines
- D59 Queen's Gambit Declined 2 lines
- D60 Queen's Gambit Declined 3 lines
- D61 Queen's Gambit Declined 1 line
- D62 Queen's Gambit Declined 1 line
- D63 Queen's Gambit Declined 6 lines
- D64 Queen's Gambit Declined 4 lines
- D65 Queen's Gambit Declined 1 line
- D66 Queen's Gambit Declined 2 lines
- D67 Queen's Gambit Declined 5 lines
- D68 Queen's Gambit Declined 3 lines
- D69 Queen's Gambit Declined 1 line
- D70 Neo-Grünfeld Defense 3 lines
- D71 Neo-Grünfeld Defense 1 line
- D72 No named lines
- D73 No named lines
- D74 Neo-Grünfeld Defense 1 line
- D75 Neo-Grünfeld Defense 2 lines
- D76 Neo-Grünfeld Defense 1 line
- D77 Neo-Grünfeld Defense 3 lines
- D78 Neo-Grünfeld Defense 1 line
- D79 Neo-Grünfeld Defense 1 line
- D80 Grünfeld Defense 7 lines
- D81 Grünfeld Defense 1 line
- D82 Grünfeld Defense 1 line
- D83 Grünfeld Defense 4 lines
- D84 Grünfeld Defense 1 line
- D85 Grünfeld Defense 7 lines
- D86 Grünfeld Defense 5 lines
- D87 Grünfeld Defense 2 lines
- D88 Grünfeld Defense 1 line
- D89 Grünfeld Defense 2 lines
- D90 Grünfeld Defense 3 lines
- D91 Grünfeld Defense 1 line
- D92 Grünfeld Defense 1 line
- D93 Grünfeld Defense 1 line
- D94 Grünfeld Defense 6 lines
- D95 Grünfeld Defense 3 lines
- D96 Grünfeld Defense 1 line
- D97 Grünfeld Defense 6 lines
- D98 Grünfeld Defense 2 lines
- D99 Grünfeld Defense 2 lines
E · Indian Defenses E00–E99
- E00 Catalan Opening & Indian Defense 6 lines
- E01 Catalan Opening 1 line
- E02 Catalan Opening 1 line
- E03 Catalan Opening 2 lines
- E04 Catalan Opening 3 lines
- E05 Catalan Opening 2 lines
- E06 Catalan Opening 3 lines
- E07 Catalan Opening 2 lines
- E08 Catalan Opening 7 lines
- E09 Catalan Opening 6 lines
- E10 Indian Defense, Blumenfeld Countergambit & more 7 lines
- E11 Bogo-Indian Defense 21 lines
- E12 Queen's Indian Defense 18 lines
- E13 Queen's Indian Defense 1 line
- E14 Queen's Indian Defense 21 lines
- E15 Queen's Indian Defense 12 lines
- E16 Queen's Indian Defense 3 lines
- E17 Queen's Indian Defense 8 lines
- E18 Queen's Indian Defense 3 lines
- E19 Queen's Indian Defense 1 line
- E20 Nimzo-Indian Defense 7 lines
- E21 Nimzo-Indian Defense 4 lines
- E22 Nimzo-Indian Defense 1 line
- E23 Nimzo-Indian Defense 4 lines
- E24 Nimzo-Indian Defense 2 lines
- E25 Nimzo-Indian Defense 3 lines
- E26 Nimzo-Indian Defense 2 lines
- E27 Nimzo-Indian Defense 1 line
- E28 Nimzo-Indian Defense 1 line
- E29 Nimzo-Indian Defense 2 lines
- E30 Nimzo-Indian Defense 2 lines
- E31 Nimzo-Indian Defense 1 line
- E32 Nimzo-Indian Defense 3 lines
- E33 Nimzo-Indian Defense 2 lines
- E34 Nimzo-Indian Defense 2 lines
- E35 Nimzo-Indian Defense 1 line
- E36 Nimzo-Indian Defense 4 lines
- E37 Nimzo-Indian Defense 3 lines
- E38 Nimzo-Indian Defense 3 lines
- E39 Nimzo-Indian Defense 2 lines
- E40 Nimzo-Indian Defense 2 lines
- E41 Nimzo-Indian Defense 3 lines
- E42 Nimzo-Indian Defense 3 lines
- E43 Nimzo-Indian Defense 12 lines
- E44 Nimzo-Indian Defense 3 lines
- E45 Nimzo-Indian Defense 1 line
- E46 Nimzo-Indian Defense 3 lines
- E47 Nimzo-Indian Defense 1 line
- E48 Nimzo-Indian Defense 2 lines
- E49 Nimzo-Indian Defense 1 line
- E50 Nimzo-Indian Defense 1 line
- E51 Nimzo-Indian Defense 3 lines
- E52 Nimzo-Indian Defense 2 lines
- E53 Nimzo-Indian Defense 3 lines
- E54 Nimzo-Indian Defense 2 lines
- E55 Nimzo-Indian Defense 1 line
- E56 Nimzo-Indian Defense 1 line
- E57 Nimzo-Indian Defense 1 line
- E58 Nimzo-Indian Defense 1 line
- E59 Nimzo-Indian Defense 2 lines
- E60 Indian Defense, King's Indian Defense & more 14 lines
- E61 King's Indian Defense 6 lines
- E62 King's Indian Defense 7 lines
- E63 King's Indian Defense 4 lines
- E64 King's Indian Defense 5 lines
- E65 King's Indian Defense 2 lines
- E66 King's Indian Defense 1 line
- E67 King's Indian Defense 2 lines
- E68 King's Indian Defense 2 lines
- E69 King's Indian Defense 1 line
- E70 King's Indian Defense 4 lines
- E71 King's Indian Defense 2 lines
- E72 King's Indian Defense 2 lines
- E73 King's Indian Defense 9 lines
- E74 King's Indian Defense 3 lines
- E75 King's Indian Defense 1 line
- E76 King's Indian Defense 3 lines
- E77 King's Indian Defense 4 lines
- E78 King's Indian Defense 1 line
- E79 King's Indian Defense 1 line
- E80 King's Indian Defense 1 line
- E81 King's Indian Defense 9 lines
- E82 King's Indian Defense 1 line
- E83 King's Indian Defense 3 lines
- E84 King's Indian Defense 1 line
- E85 King's Indian Defense 1 line
- E86 King's Indian Defense 1 line
- E87 King's Indian Defense 3 lines
- E88 King's Indian Defense 1 line
- E89 King's Indian Defense 1 line
- E90 King's Indian Defense 3 lines
- E91 King's Indian Defense 2 lines
- E92 King's Indian Defense 5 lines
- E93 King's Indian Defense 2 lines
- E94 King's Indian Defense 6 lines
- E95 King's Indian Defense 1 line
- E96 King's Indian Defense 1 line
- E97 King's Indian Defense 6 lines
- E98 King's Indian Defense 3 lines
- E99 King's Indian Defense 2 lines