Chess puzzle (Advantage)
Moves: 1. b3 d5 2. Bb2 Nc6 3. e3 e5 4. Bb5 Bd6 5. f4 Qe7 6. Nf3 f6 7. Nc3 Bd7 8. Nxd5
Qf7 9. fxe5 Qxd5 10. Bxc6 Bxc6 11. exd6 Qxd6 12. O-O O-O-O 13. Nd4 Be4 14. Qg4+
Kb8 15. Qxe4 Ne7 16. d3 h5 17. Ne6 Rde8 18. Nxg7 Rhg8 19. Nxh5 Nd5 20. Qf4 *
Position (FEN): 1k2r1r1/ppp5/3q1p2/3n3N/5Q2/1P1PP3/PBP3PP/R4RK1 b - - 2 20
Black to move.
Themes:  Middlegame  
Puzzle rating: 1011
Best move: Nxf4