Queen's Gambit Declined: Alekhine Variation

The Queen's Gambit Declined: Alekhine Variation is a chess opening classified under ECO code D51 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 6 moves: 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Nbd7 5. Nf3 c6 6. e4. The resulting position leaves black to move.