Queen's Gambit Declined: Harrwitz Attack

The Queen's Gambit Declined: Harrwitz Attack is a chess opening classified under ECO code D37 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 10 moves: 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 5. Bf4 O-O 6. e3 c5 7. dxc5 Bxc5 8. Qc2 Nc6 9. a3 Qa5 10. O-O-O. The resulting position leaves black to move.