Chess puzzle (Checkmate)
Opening: Queens_Gambit_Declined, Queens_Gambit_Declined_Marshall_Defense
Moves: 1. d4 d5 2. c4 Nf6 3. cxd5 g6 4. Bg5 Bg7 5. Nc3 Nxd5 6. e4 Nxc3 7. bxc3 O-O 8.
h4 h6 9. Bf4 Nd7 10. h5 g5 11. Bd2 e5 12. Nf3 exd4 13. cxd4 Nf6 14. e5 Ne4 15.
Bd3 Nxd2 16. Qxd2 Bg4 17. Bc2 Bxf3 18. gxf3 Qd7 19. Qd3 Rad8 *
Position (FEN): 3r1rk1/pppq1pb1/7p/4P1pP/3P4/3Q1P2/P1B2P2/R3K2R w KQ - 3 20
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 399
Best move: Qh7#