Sicilian Defense: Richter-Rauzer Variation, Classical Variation, Kantscher Line

The Sicilian Defense: Richter-Rauzer Variation, Classical Variation, Kantscher Line is a chess opening classified under ECO code B63 in the Semi-Open Games family, where Black responds to 1.e4 with something other than 1...e5, including the Sicilian Defense, Caro-Kann, and Pirc. It is reached after 10 moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. Bg5 e6 7. Qd2 Be7 8. O-O-O Nxd4 9. Qxd4 a6 10. f4 b5. The resulting position leaves white to move.