Chess puzzle (Checkmate)
Opening: Vienna_Game, Vienna_Game_Anderssen_Defense
Moves: 1. e4 e5 2. Nc3 Bc5 3. Bc4 Nc6 4. Qg4 d5 5. Qxg7 Qf6 6. Qxf6 Nxf6 7. Nxd5 Nxd5
8. Bxd5 Nd4 9. Kd1 c6 10. Bb3 Nxb3 11. axb3 Bxf2 12. Nh3 *
Position (FEN): r1b1k2r/pp3p1p/2p5/4p3/4P3/1P5N/1PPP1bPP/R1BK3R b kq - 1 12
Black to move.
Themes:  Middlegame Double Bishop Mate, Mate in 1 
Puzzle rating: 870
Best move: Bg4#