B67 Sicilian Defence: Richter-Rauzer, 7.Qd2 a6 8.O-O-O Bd7

After 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 e6 7.Qd2 a6 8.O-O-O Bd7, the Richter-Rauzer Attack of the Sicilian Defence reaches ECO code B67. White's 6.Bg5 pins the knight on f6 and adds pressure on d6. The plan is to castle queenside and attack with f4, sometimes doubling Black's f-pawns with Bxf6. Black answers with ...a6 and ...Bd7, then castles kingside or leaves the king in the centre. The bishop on d7 connects the rooks and backs up a queenside pawn storm with ...b5. The usual result is opposite-side castling and a race between the two attacks.