Chess puzzle (Checkmate)
Opening: Queens_Gambit_Declined, Queens_Gambit_Declined_Exchange_Variation
Moves: 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cxd5 exd5 5. Bg5 c6 6. e3 Be7 7. Bd3 Nbd7 8.
Qc2 Nh5 9. Bxe7 Qxe7 10. Nge2 g6 11. O-O-O Nb6 12. h3 Be6 13. Kb1 O-O-O 14. Rc1
Kb8 15. Na4 Nxa4 16. Qxa4 Nf6 17. Rc3 Rc8 18. Ra3 b6 19. Rc1 Qd6 *
Position (FEN): 1kr4r/p4p1p/1ppqbnp1/3p4/Q2P4/R2BP2P/PP2NPP1/1KR5 w - - 2 20
White to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 763
Best move: Qxa7#