ECO index: E00--E99

E00: Neo-Indian, various early moves: 1. d4 Nf6 2. c4 e6

E01: Catalan Opening, early deviations: 1. d4 Nf6 2. c4 e6 3. g3 d5

E02: Open Catalan with 5.Qa4+: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+

E03: Open Catalan, 5.Qa4+ Nbd7 6.Qxc4: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. Qxc4

E04: Open Catalan, 5.Nf3: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3

E05: Open Catalan, Classical: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3 Be7

E06: Closed Catalan sidelines: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 Be7

E07: Closed Catalan, 5.Nf3 O-O 6.O-O Nbd7: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 Be7 5. Nf3 O-O 6. O-O Nbd7

E08: Closed Catalan, 7.Qc2: 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 Be7 5. Nf3 O-O 6. O-O Nbd7 7. Qc2

E09: Closed Catalan, Main Line: 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

E10: Neo-Indian with 3.Nf3, sidelines: 1. d4 Nf6 2. c4 e6 3. Nf3

E11: Bogo-Indian Defence: 1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+

E12: Queen's Indian Defence, early deviations: 1. d4 Nf6 2. c4 e6 3. Nf3 b6

E13: Queen's Indian Defence, 4.Nc3, Main Line: 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Nc3 Be7 5. Bg5

E14: Queen's Indian Defence, 4.e3 : 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. e3

E15: Queen's Indian Defence, 4.g3 : 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3

E16: Queen's Indian Defence, 4.g3 Bb7 (without 5.Bg2 or 5...Be7): 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7

E17: Queen's Indian Defence, 5.Bg2 Be7: 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7

E18: Queen's Indian Defence, 7.Nc3: 1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7 6. O-O O-O 7. Nc3

E19 Queen's Indian, Old Main Line, 8.Qc2: 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 Neo-Indian with 3.Nc3, sidelines (including early deviations after 3...Bb4, i.e. after Nimzo-Indian Defence): 1. d4 Nf6 2. c4 e6 3. Nc3

E21 Nimzo-Indian, Three Knights Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Nf3

E22 Nimzo-Indian, Spielmann Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3

E23 Nimzo-Indian, Spielmann, 4...c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5

E24 Nimzo-Indian, Sämisch Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3

E25 Nimzo-Indian, Sämisch, 5.bxc3 c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 c5

E26 Nimzo-Indian, Sämisch, 5.bxc3 c5 6.e3: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 c5 6. e3

E27 Nimzo-Indian, Sämisch, 5.bxc3 O-O: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 O-O

E28 Nimzo-Indian, Sämisch, 5.bxc3 O-O 6.e3: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 O-O 6. e3

E29 Nimzo-Indian, Sämisch, 5...O-O 6.e3 c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 O-O 6. e3 c5

E30 Nimzo-Indian, Leningrad Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bg5

E31 Nimzo-Indian, Leningrad, Main Line: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bg5 h6 5. Bh4 c5 6. d5 d6

E32 Nimzo-Indian, Classical Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2

E33 Nimzo-Indian, Classical, 4...Nc6: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 Nc6

E34 Nimzo-Indian, Classical, Noa Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5

E35 Nimzo-Indian, Classical, Noa, Exchange Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. cxd5 exd5

E36 Nimzo-Indian, Classical, Noa, 5.a3: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. a3

E37 Nimzo-Indian, Classical, Noa, Main Line: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. a3 Bxc3+ 6. Qxc3 Ne4

E38 Nimzo-Indian, Classical, 4...c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5

E39 Nimzo-Indian, Classical, Pirc Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5 5. dxc5 O-O

E40 Nimzo-Indian with 4.e3 (Rubinstein System), early deviations: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3

E41 Nimzo-Indian, 4.e3 c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5

E42 Nimzo-Indian, Rubinstein Variation, Main Line: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Ne2

E43 Nimzo-Indian, 4.e3 b6 (Nimzowitsch System): 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6

E44 Nimzo-Indian, 4.e3 b6 5.Ne2: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Ne2

E45 Nimzo-Indian, Fischer Variation: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Ne2 Ba6

E46 Nimzo-Indian, 4.e3 O-O: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O

E47 Nimzo-Indian, 4.e3 O-O 5.Bd3: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3

E48 Nimzo-Indian, 4.e3 O-O 5.Bd3 d5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5

E49 Nimzo-Indian, 4.e3 O-O 5.Bd3 d5 6.a3 (Botvinnik Variation Deferred): 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. a3

E50 Nimzo-Indian, 4.e3 O-O, 5.Nf3, without 5...d5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3

E51 Nimzo-Indian, 4.e3 O-O, 5.Nf3 d5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3 d5

E52 Nimzo-Indian, 4.e3, Classical Main Line with 6...b6: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3 d5 6. Bd3 b6

E53 Nimzo-Indian, 4.e3, Classical Main Line with 6...c5: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3 d5 6. Bd3 c5

E54 Nimzo-Indian, 4.e3, Gligoric System, 7...dxc4 8.Bxc4: 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

E55 Nimzo-Indian, 4.e3, Gligoric System, Bronstein Variation: 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

E56 Nimzo-Indian, 4.e3, Classical Main Line with 7...Nc6: 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Nf3 d5 6. Bd3 c5 7. O-O Nc6

E57 Nimzo-Indian, 4.e3, Classical Main Line with 8...dxc4, 9...Bxc4 cxd4: 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 Nimzo-Indian, 4.e3, Classical Main Line with 8...Bxc3: 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 Nimzo-Indian, 4.e3, Classical Main Line: 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

E60-E99

E60 King's Indian Defence, various early moves: 1. d4 Nf6 2. c4 g6

E61 King's Indian Defence with 3.Nc3, early deviations: 1. d4 Nf6 2. c4 g6 3. Nc3

E62 King's Indian, Fianchetto Variation, sidelines: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3

E63 King's Indian, Fianchetto, 6.Bg2 Nc6: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 O-O 6. Bg2 Nc6 7. O-O a6

E64 King's Indian, Fianchetto, Yugoslav System: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 O-O 6. Bg2 c5

E65 King's Indian, Yugoslav, 7.O-O: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 O-O 6. Bg2 c5 7. O-O

E66 King's Indian, Fianchetto, Yugoslav Panno: 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

E67 King's Indian, Fianchetto with 6...Nbd7: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 O-O 6. Bg2 Nbd7

E68 King's Indian, Fianchetto, Classical Variation, 8.e4: 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 King's Indian, Fianchetto, Classical, Main Line: 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

E70 King's Indian with 4.e4, early deviations: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4

E71 King's Indian, Makogonov System: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. h3

E72 King's Indian, 4.e4 d6 5.g3: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. g3

E73 King's Indian, 5.Be2: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2

E74 King's Indian, Averbakh, 6...c5: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2 O-O 6. Bg5 c5

E75 King's Indian, Averbakh, Main Line: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2 O-O 6. Bg5 c5 7. d5 e6

E76 King's Indian Defence, Four Pawns Attack: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f4

E77 King's Indian, Four Pawns Attack, 6.Be2: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f4 O-O 6. Be2

E78 King's Indian, Four Pawns Attack, 6.Be2 c5 7.Nf3: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f4 O-O 6. Be2 c5 7. Nf3

E79 King's Indian, Four Pawns Attack, Main Line: 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

E80 King's Indian, Sämisch Variation, sidelines: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3

E81 King's Indian, Sämisch, 5...O-O: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O

E82 King's Indian, Sämisch, Double Fianchetto Variation: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 b6

E83 King's Indian, Sämisch, 6...Nc6: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 Nc6

E84 King's Indian, Sämisch, Panno Main Line: 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

E85 King's Indian, Sämisch, Orthodox Variation: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 e5

E86 King's Indian, Sämisch, Orthodox, 7.Nge2 c6: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 e5 7. Nge2 c6

E87 King's Indian, Sämisch, Orthodox, 7.d5: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 e5 7. d5

E88 King's Indian, Sämisch, Orthodox, 7.d5 c6: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Be3 e5 7. d5 c6

E89 King's Indian, Sämisch, Orthodox, Main Line: 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 King's Indian with 5.Nf3, sidelines: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3

E91 King's Indian, 5.Nf3 O-O 6.Be2: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2

E92 King's Indian, Classical Variation, sidelines: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5

E93 King's Indian, Classical, Petrosian System, Main Line: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. d5 Nbd7

E94 King's Indian, Orthodox Variation: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O

E95 King's Indian, Orthodox, 7...Nbd7: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nbd7

E96 King's Indian, Orthodox, 7...Nbd7 8.Re1: 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

E97 King's Indian, Orthodox, Mar del Plata Variation: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6

E98 King's Indian, Orthodox, Mar del Plata, 9.Ne1: 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

E99 King's Indian, Orthodox, Mar del Plata, Main Line: 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

ECO volumes

External links

Chess Informant official website
Bill Wall's list of opening variations
Chess Archaeology: Openings classified ECO E00-E99 from chessarch.com