Sicilian Defense: Smith-Morra Gambit Accepted, Chicago Defense

The Sicilian Defense: Smith-Morra Gambit Accepted, Chicago Defense is a chess opening classified under ECO code B21 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 7 moves: 1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 d6 5. Nf3 e6 6. Bc4 Nf6 7. O-O a6. The resulting position leaves white to move.