The 500 ECO Codes – Full Overview of the Classical Opening System

 

Indian Defences

 

E00 Queen’s Pawn Game (including Neo-Indian Attack, Trompowsky Attack, Catalan Opening and others)
1. d4 Nf6 2. c4 e6

 

E01 Catalan, Closed
1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2

 

E02 Catalan, open, 5.Qa4
1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+

 

E03 Catalan, open, Alekhine Variation
1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. Qxc4 a6 7. Qc2

 

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

 

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

 

E06 Catalan, Closed, 5.Nf3
1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Nf3

 

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

 

E08 Catalan, Closed, 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 Catalan, Closed, 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 Queen’s Pawn Game 3.Nf3
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
1. d4 Nf6 2. c4 e6 3. Nf3 b6

 

E13 Queen’s Indian, 4.Nc3, Main line
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. Nc3 Bb7 5. Bg5 h6 6. Bh4 Bb4

 

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

 

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

 

E16 Queen’s Indian, Capablanca Variation
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Bb4+

 

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

 

E18 Queen’s Indian, Old Main line, 7.Nc3
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7 6. 0-0 0-0 7. Nc3

 

E19 Queen’s Indian, Old Main line, 9.Qxc3
1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Bb7 5. Bg2 Be7 6. 0-0 0-0 7. Nc3 Ne4 8. Qc2 Nxc3 9. Qxc3

 

E20 Nimzo-Indian Defence
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4

 

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, 5.dxc5 Nc6
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6

 

E24 Nimzo-Indian, Sämisch Variation
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3

 

E25 Nimzo-Indian, Sämisch Variation, Keres Variation
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 c5 6. f3 d5 7. cxd5

 

E26 Nimzo-Indian, Sämisch Variation, 4.a3 Bxc3+ 5.bxc3 c5 6.e3
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 0-0 6. e3

 

E27 Nimzo-Indian, Sämisch Variation, 5…0-0
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 O-O

 

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

 

E29 Nimzo-Indian, Sämisch Variation, Main line
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 0-0 6. e3 c5 7. Bd3 Nc6

 

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

 

E31 Nimzo-Indian, Leningrad Variation, 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 (4.Qc2)
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2

 

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

 

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

 

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

 

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

 

E37 Nimzo-Indian, Classical, Noa Variation, Main line, 7.Qc2
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. a3 Bxc3+ 6. Qxc3 Ne4 7. Qc2

 

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 0-0

 

E40 Nimzo-Indian, 4.e3
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, 4.e3 c5, 5.Ne2 (Rubinstein)
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Ne2

 

E43 Nimzo-Indian, Fischer Variation
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6

 

E44 Nimzo-Indian, Fischer Variation, 5.Ne2
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Nge2

 

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

 

E46 Nimzo-Indian, 4.e3 0-0
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0

 

E47 Nimzo-Indian, 4.e3 0-0, 5.Bd3
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Bd3

 

E48 Nimzo-Indian, 4.e3 0-0, 5.Bd3 d5
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Bd3 d5

 

E49 Nimzo-Indian, 4.e3, Botvinnik System
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Bd3 d5 6. a3 Bxc3+

 

E50 Nimzo-Indian, 4.e3 0-0, 5.Nf3, without …d5
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3

 

E51 Nimzo-Indian, 4.e3 0-0, 5.Nf3 d5
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5

 

E52 Nimzo-Indian, 4.e3, Main line with …b6
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 b6

 

E53 Nimzo-Indian, 4.e3, Main line with …c5
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5

 

E54 Nimzo-Indian, 4.e3, Gligoric System with 7…dxc4
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5 7. 0-0 dxc4 8. Bxc4

 

E55 Nimzo-Indian, 4.e3, Gligoric System, Bronstein Variation
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5 7. 0-0 dxc4 8. Bxc4 Nbd7

 

E56 Nimzo-Indian, 4.e3, Main line with 7…Nc6
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5 7. 0-0 Nc6

 

E57 Nimzo-Indian, 4.e3, Main line with 8…dxc4 and 9…Bxc4 cxd4
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5 7. 0-0 Nc6 8. a3 dxc4 9. Bxc4 cxd4

 

E58 Nimzo-Indian, 4.e3, Main line with 8…Bxc3
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 0-0 5. Nf3 d5 6. Bd3 c5 7. 0-0 Nc6 8. a3 Bxc3+ 9.bxc3

 

E59 Nimzo-Indian, 4.e3, 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 King’s Indian Defence
1. d4 Nf6 2. c4 g6

 

E61 King’s Indian Defence, 3.Nc3
1. d4 Nf6 2. c4 g6 3. Nc3

 

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

 

E63 King’s Indian, Fianchetto, Panno Variation
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 0-0 6. Bg2 Nc6 7. 0-0 a6

 

E64 King’s Indian, Fianchetto, Yugoslav System
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 0-0 6. Bg2 c5

 

E65 King’s Indian, Yugoslav, 7.0-0
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 0-0 6. Bg2 c5 7. 0-0

 

E66 King’s Indian, Fianchetto, Yugoslav Panno
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 0-0 6. Bg2 c5 7. 0-0 Nc6 8. d5

 

E67 King’s Indian, Fianchetto with …Nd7
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5. g3 0-0 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 0-0 6. Bg2 Nbd7 7. 0-0 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 0-0 6. Bg2 Nbd7 7. 0-0 e5 8. e4 c6 9. h3

 

E70 King’s Indian, 4.e4
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4

 

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

 

E72 King’s Indian with e4 and 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 0-0 6. Bg5 c5 7. d5 e6

 

E76 King’s Indian, 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 0-0 6. Be2

 

E78 King’s Indian, Four Pawns Attack, with Be2 and Nf3
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f4 0-0 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 0-0 6. Be2 c5 7. Nf3 cxd4 8. Nxd4 Nc6 9. Be3

 

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

 

E81 King’s Indian, Sämisch, 5…0-0
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 0-0

 

E82 King’s Indian, Sämisch, Double Fianchetto Variation
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 0-0 6. Be3 b6

 

E83 King’s Indian, Sämisch, 6…Nc6 (Panno Variation)
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 0-0 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 0-0 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 0-0 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 0-0 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 0-0 6. Be3 e5 7. d5 c6 8. Nge2

 

E90 King’s Indian, 5.Nf3
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3

 

E91 King’s Indian, 6.Be2
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2

 

E92 King’s Indian, Classical Variation
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5

 

E93 King’s Indian, Petrosian System, Main line
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 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 0-0 6. Be2 e5 7. 0-0

 

E95 King’s Indian, Orthodox, 7…Nbd7, 8.Re1
1.d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. 0-0 Nbd7 8. Re1

 

E96 King’s Indian, Orthodox, 7…Nbd7, Main line
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. 0-0 Nbd7 8. Re1 c6 9. Bf1 a5

 

E97 King’s Indian, Orthodox, Aronin–Taimanov Variation (Yugoslav Attack / Mar del Plata Variation)
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. 0-0 Nc6

 

E98 King’s Indian, Orthodox, Aronin–Taimanov, 9.Ne1
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. 0-0 Nc6 8. d5 Ne7 9. Ne1

 

E99 King’s Indian, Orthodox, Aronin–Taimanov, Main
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. 0-0 Nc6 8. d5 Ne7 9. Ne1 Nd7 10. f3

 

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