Chess puzzle (Checkmate)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 h6 4. O-O d5 5. Bxc6+ bxc6 6. Nxe5 dxe4 7. Nxc6 Qd6
8. Na5 Nf6 9. Re1 Qe5 10. Nb3 Bd6 11. g3 Bh3 12. d3 O-O 13. Bf4 Qd5 14. Bxd6
exd3 15. f3 cxd6 16. Qxd3 Qc6 17. Nc3 Qb6+ 18. Kh1 Rfe8 19. Ne4 Nxe4 20. fxe4
Qf2 21. Qe2 *
Position (FEN): r3r1k1/p4pp1/3p3p/8/4P3/1N4Pb/PPP1Qq1P/R3R2K b - - 2 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1257
Best move: Bg2#