Semi-Averbakh Variation, Polish Variation

This line reaches a Modern Defense structure by way of a flank move order, 1. Nf3 c5 2. c4, and ECO files it under A04. White ends up with pawns on c4, d4 and e4, much as in the Averbakh System. Instead of ...d6, Black plays 4...Qb6. The queen adds to the pressure that the c5-pawn and the g7-bishop already exert on d4, and it also eyes b2. White must then either hold d4 or resolve the central tension. The queen's early sortie can become a target for White's developing moves.