Queen's Gambit Accepted: Alekhine Defense, Borisenko-Furman Variation

The Queen's Gambit Accepted: Alekhine Defense, Borisenko-Furman Variation is a chess opening classified under ECO code D21 in the Closed & Semi-Closed Games family, arising from 1.d4 d5, including the Queen's Gambit, Slav Defense, and related systems. It is reached after 4 moves: 1. d4 d5 2. c4 dxc4 3. Nf3 a6 4. e4. The resulting position leaves black to move.