Chess puzzle (Checkmate)
Opening: Semi-Slav_Defense, Semi-Slav_Defense_Meran_Variation
Moves: 1. d4 d5 2. c4 e6 3. Nf3 c6 4. e3 Nf6 5. Bd3 Nbd7 6. Nc3 dxc4 7. Bxc4 b5 8. Be2
a6 9. e4 Bb7 10. e5 Nd5 11. Nxd5 cxd5 12. a3 Nb6 13. Bd3 Nc4 14. O-O Be7 15.
Ne1 O-O 16. Qg4 h6 17. Bxh6 g6 18. Bxg6 f5 19. Bh7+ Kxh7 *
Position (FEN): r2q1r2/1b2b2k/p3p2B/1p1pPp2/2nP2Q1/P7/1P3PPP/R3NRK1 w - - 0 20
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1009
Best move: Qg7#