Chess puzzle (Checkmate)
Opening: Vienna_Game, Vienna_Game_Anderssen_Defense
Moves: 1. e4 e5 2. Nc3 Bc5 3. Bc4 d6 4. Nge2 Bg4 5. O-O Nc6 6. h3 Bh5 7. d3 h6 8. Be3
Bb4 9. Nd5 Nf6 10. Nxb4 Nxb4 11. c3 Nc6 12. Qd2 O-O 13. Ng3 Bg6 14. Bxh6 gxh6
15. Qxh6 Nh7 16. Nf5 Bxf5 17. exf5 Ne7 18. g4 Kh8 19. f6 Ng6 *
Position (FEN): r2q1r1k/ppp2p1n/3p1PnQ/4p3/2B3P1/2PP3P/PP3P2/R4RK1 w - - 1 20
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 900
Best move: Qg7#