Chess puzzle (Checkmate)
Moves: 1. d4 Nf6 2. c4 e6 3. a3 d5 4. Nc3 c5 5. cxd5 cxd4 6. Qa4+ Bd7 7. Qxd4 exd5 8.
Nxd5 Qa5+ 9. Nc3 Nc6 10. Qd1 Ne4 11. Bd2 Nxd2 12. Qxd2 O-O-O 13. Rc1 Be6 14.
Qf4 Nd4 15. Nf3 Nb3 16. Rd1 Bxa3 17. Qa4 Rxd1+ 18. Kxd1 Rd8+ 19. Kc2 Na1+ 20.
Kb1 Qxa4 21. Nxa4 *
Position (FEN): 2kr4/pp3ppp/4b3/8/N7/b4N2/1P2PPPP/nK3B1R b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 782
Best move: Rd1#