About this opening
Nimzo-Indian Defense: Classical Variation, Modern Variation is an opening in the Encyclopedia of Chess Openings,
classified under code E37. ECO group E (E00–E99)
covers Indian defences against 1.d4, covering the Nimzo-Indian, Queen's Indian, King's Indian and Catalan systems. This particular variation is reached
after 14 half-moves from the
starting position, with the move sequence 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. a3 Bxc3+ 6. Qxc3 Ne4 7. Qc2 c5.
It belongs to the Nimzo-Indian Defense family.
Within that family this is a level-2 branch (the Classical Variation → Modern Variation line). The immediate parent line is Nimzo-Indian Defense: Classical Variation, transitioned via 7…c5.
The opening sequence in prose form: 1.d4 Nf6, 2.c4 e6, 3.Nc3 Bb4, 4.Qc2 d5, 5.a3 Bxc3+, 6.Qxc3 Ne4. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.
Use the interactive board above to walk through the moves position-by-position. Click any move in the navigation to step backwards, or use the keyboard arrow keys. For statistical data — how often master-level players have reached this position, White's win-rate, draw frequency, Black's score — see the panel in the right column.
Caissly's coverage of E37 extends through every named sub-variation in this line and across all four locales (English, Spanish, Portuguese, Russian). Where editorial commentary exists for a specific variation it appears as the page body; otherwise the page presents the structural data, board, and statistics as shown here.