Chess puzzle (Checkmate)
Opening: Caro-Kann_Defense, Caro-Kann_Defense_Classical_Variation
Moves: 1. d4 d5 2. Nc3 c6 3. e4 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. f4 e6 7. Nf3 h6 8. Bd3
Bxd3 9. Qxd3 Ne7 10. Bd2 g6 11. O-O-O Bg7 12. Kb1 Nd7 13. h4 h5 14. Rhe1 Qc7
15. Ne5 Nxe5 16. dxe5 Rd8 17. Qa3 b6 18. Ne4 Nf5 19. g3 Bf8 *
Position (FEN): 3rkb1r/p1q2p2/1pp1p1p1/4Pn1p/4NP1P/Q5P1/PPPB4/1K1RR3 w k - 1 20
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 877
Best move: Nf6#