Chess puzzle (Checkmate)
Opening: Nimzowitsch_Defense, Nimzowitsch_Defense_Declined_Variation
Moves: 1. e4 Nc6 2. Nf3 d5 3. exd5 Qxd5 4. Nc3 Qa5 5. d4 Bg4 6. Bb5 O-O-O 7. Bxc6 bxc6
8. h3 Qh5 9. Qd3 Bxf3 10. gxf3 Kb7 11. Be3 Nf6 12. O-O-O e6 13. Ne4 Qxf3 14.
Qb3+ Ka8 15. Nxf6 gxf6 16. Qa4 Rb8 17. d5 cxd5 *
Position (FEN): kr3b1r/p1p2p1p/4pp2/3p4/Q7/4Bq1P/PPP2P2/2KR3R w - - 0 18
White to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 1614
Best move: Qxa7#