B63 Sicilian Defence: Richter-Rauzer, Classical (7...Be7 8.O-O-O O-O)

ECO code B63 covers the Richter-Rauzer Attack against the Classical Sicilian: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. Bg5 e6 7. Qd2. White's 6.Bg5 stops Black from playing the Dragon set-up with ...g6. It pins the knight on f6 and threatens to double Black's f-pawns with Bxf6. With 7.Qd2, White connects the rooks and prepares queenside castling. After 7...Be7 8.O-O-O O-O, the kings sit on opposite wings. White usually aims for f4 and a kingside pawn storm or pressure on d6. Black seeks counterplay on the queenside and in the centre, often with ...a6, ...b5 or a timely ...d5.