Chess puzzle (Checkmate)
Opening: Vant_Kruijs_Opening, Vant_Kruijs_Opening_Other_variations
Moves: 1. e3 Nf6 2. a3 e6 3. h3 c5 4. d4 Nc6 5. Nf3 d6 6. dxc5 dxc5 7. Qxd8+ Nxd8 8.
Bb5+ Bd7 9. Bxd7+ Kxd7 10. Nc3 a6 11. e4 Kc7 12. Bf4+ Kc8 13. O-O-O Be7 14. Na4
Ra7 *
Position (FEN): 2kn3r/rp2bppp/p3pn2/2p5/N3PB2/P4N1P/1PP2PP1/2KR3R w - - 7 15
White to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 840
Best move: Nb6#