Sicilian Defense: Wing Gambit, Marienbad Variation

The Sicilian Defense: Wing Gambit, Marienbad Variation is a chess opening classified under ECO code B20 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 5 moves: 1. e4 c5 2. b4 cxb4 3. a3 d5 4. exd5 Qxd5 5. Bb2. The resulting position leaves black to move.