ECO A90

ECO A00–A99 — Flank openings: 1.c4, 1.Nf3, 1.f4 and other first moves, plus early Indian and Benoni systems.

3 named opening lines are classified under ECO code A90.

• Dutch Defense: Nimzo-Dutch Variation — 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Bb4+
• Dutch Defense: Nimzo-Dutch Variation, Alekhine Variation — 1.d4 f5 2.c4 Nf6 3.g3 e6 4.Bg2 Bb4+ 5.Bd2 Be7
• Dutch Defense: Stonewall Variation, Modern Variation — 1.d4 f5 2.c4 e6 3.Nf3 Nf6 4.g3 c6 5.Bg2 d5 6.O-O Bd6