Chess puzzle (Checkmate)
Moves: 1. e4 d6 2. d4 Nf6 3. Nc3 g6 4. Nf3 Bg7 5. Be3 O-O 6. Qd2 Ng4 7. Bf4 e5 8. Bg3
exd4 9. Nxd4 Ne5 10. f4 Nec6 11. Nf3 Bg4 12. Bc4 Bxf3 13. gxf3 Nd4 14. Qf2 Nbc6
15. O-O-O Na5 16. Rxd4 c5 17. Bxf7+ Rxf7 18. Rd5 Nc4 19. Rhd1 Qb6 20. b3 Bxc3
21. bxc4 *
Position (FEN): r5k1/pp3r1p/1q1p2p1/2pR4/2P1PP2/2b2PB1/P1P2Q1P/2KR4 b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1458
Best move: Qb2#