Nimzo-Indian Defense: Rubinstein System, Rubinstein Variation, Sherbakov Attack
ECO E42
Move order
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Ne2 cxd4 6. exd4 O-O 7. c5
Ideas
ECO E covers Indian defenses and related systems where Black fianchettoes or pressures the center from the flanks. White builds a pawn center and keeps the position more closed than after 1. e4. This entry tracks a longer branch in the opening tree. Use the diagram and SAN list to recognize the tabiya, then try the line against Maia to explore typical plans in practice.