Chess puzzle (Checkmate)
Moves: 1. d4 g6 2. e4 c5 3. Be3 Bg7 4. Nc3 cxd4 5. Bxd4 e5 6. Bc5 Ne7 7. Nf3 O-O 8.
Qd6 Nbc6 9. Nb5 Qa5+ 10. c3 b6 11. Bb4 Nxb4 12. cxb4 Qa4 13. b3 Qa6 14. Qxe7
Qb7 15. Nd6 Qc6 16. Bc4 Ba6 17. b5 Qc5 18. bxa6 Rfe8 19. Qxf7+ Kh8 20. Qg8+
Rxg8 *
Position (FEN): r5rk/p2p2bp/Pp1N2p1/2q1p3/2B1P3/1P3N2/P4PPP/R3K2R w KQ - 0 21
White to move.
Themes:  Middlegame Mate in 1, Smothered Mate 
Puzzle rating: 831
Best move: Nf7#