1...c5 creates an asymmetric game: White gets the d-file and kingside chances, Black gets the half-open c-file and a central pawn majority.
Key principles
- Black's counterplay comes on the c-file and with ...b5
- The ...d5 break frees Black's game when it can be played safely
- Opposite-side castling makes speed of attack decisive
Common mistakes
- Playing ...d5 too early and losing a pawn
- Slow queenside play while White attacks the king