Nimzo-Indian Defence - ECO Codes

ECO Codes

In the Encyclopaedia of Chess Openings, the Nimzo-Indian Defence has codes E20 to E59. All codes begin with 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4, excluding E20, which also includes alternatives to 3...Bb4 apart from 3...d5 (which would be the Queen's Gambit Declined).

E20 - 1.d4 Nf6 2.c4 e6 3.Nc3 (includes Romanishin Variation, 4.f3 Variation of Nimzo-Indian excluding 4.f3 d5 5.a3 Bxc3+, which is covered under E25)

E21 - 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 (Kasparov Variation excluding 4...c5 5.g3, which is covered under E20)

E22 - 4.Qb3 (E22 and E23 cover the Spielmann Variation)

E23 - 4.Qb3 c5

E24 - 4.a3 (E24-E29 cover the Sämisch Variation)

E25 - 4.a3 Bxc3+ 5.bxc3 c5

E26 - 4.a3 Bxc3+ 5.bxc3 c5 6.e3

E27 - 4.a3 Bxc3+ 5.bxc3 0-0

E28 - 4.a3 Bxc3+ 5.bxc3 0-0 6.e3

E29 - 4.a3 Bxc3+ 5.bxc3 0-0 6.e3 c5

E30 - 4.Bg5 (E30 and E31 cover the Leningrad Variation)

E31 - 4.Bg5 h6 6.Bh4 c5 6.d5 d6

E32 - 4.Qc2 (includes 4...0-0; E32-E39 cover the Classical/Capablanca Variation)

E33 - 4.Qc2 Nc6 (Zürich/Milner-Barry Variation)

E34 - 4.Qc2 d5

E35 - 4.Qc2 d5 5.cxd5 exd5

E36 - 4.Qc2 d5 5.a3

E37 - 4.Qc2 d5 5.a3 Bxc3+ 6.Qxc3 Ne4

E38 - 4.Qc2 c5

E39 - 4.Qc2 c5 5.dxc5 0-0

E40 - 4.e3 (includes Taimanov Variation; E40-E59 cover the Rubinstein System)

E41 - 4.e3 c5 (includes Hübner Variation)

E42 - 4.e3 c5 5.Ne2 (Rubinstein Variation, Romanishin-Psakhis Variation via 5...b6 6.a3 Ba5)

E43 - 4.e3 b6 (includes Dutch Variation, Keres Variation)

E44 - 4.e3 b6 5.Ne2 (includes American Variation, 5...Bb7 Variation)

E45 - 4.e3 b6 5.Ne2 Ba6 (Fischer Variation)

E46 - 4.e3 0-0 (includes Reshevsky Variation)

E47 - 4.e3 0-0 5.Bd3

E48 - 4.e3 0-0 5.Bd3 d5 (includes Modern Variation)

E49 - 4.e3 0-0 5.Bd3 d5 6.a3

E50 - 4.e3 0-0 5.Nf3

E51 - 4.e3 0-0 5.Nf3 d5

E52 - 4.e3 0-0 5.Nf3 d5 6.Bd3 b6 (Classical Fianchetto/Tal Variation)

E53 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 (includes Averbakh Variation)

E54 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 dxc4 8.Bxc4 (includes Karpov Variation, Bronstein Variation, Smyslov Variation)

E55 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 dxc4 8.Bxc4 Nbd7 (Parma Variation)

E56 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 Nc6 (includes Larsen Variation)

E57 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 Nc6 8.a3 dxc4 9.Bxc4 cxd4

E58 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 Nc6 8.a3 Bxc3 9.bxc3 (includes Khasin Variation)

E59 - 4.e3 0-0 5.Nf3 d5 6.Bd3 c5 7.0-0 Nc6 8.a3 Bxc3 9.bxc3 dxc4 10.Bxc4 (includes Main Variation)