Voir : 12 24 Tous E20 Nimzo-Indian defence 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4... (1) E21 Nimzo-Indian: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3 three knights variation (1) E32-E39 Nimzo-Indian: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 classical variation (3) E40-E49 Nimzo-Indian: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 Rubinstein 4.e3 ... (1)