Chess puzzle (Advantage)
Moves: 1. e4 e6 2. Qe2 d5 3. exd5 Qxd5 4. Nc3 Qd8 5. Nf3 Be7 6. d4 Nf6 7. Bg5 Nbd7 8.
O-O-O c6 9. Kb1 Qa5 10. Bd2 Qc7 11. Re1 O-O 12. g3 b5 13. Ne5 Bb7 14. Bg2 Rac8
15. a3 a5 16. Ne4 Nxe5 17. Bf4 Nfd7 18. dxe5 b4 19. axb4 axb4 20. Nf6+ Nxf6 *
Position (FEN): 2r2rk1/1bq1bppp/2p1pn2/4P3/1p3B2/6P1/1PP1QPBP/1K2R2R w - - 0 21
White to move.
Themes:  Middlegame  
Puzzle rating: 1124
Best move: exf6