Chess puzzle (Advantage)
Moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 e5 5. Nf5 g6 6. Ne3 Nf6 7. Bd3 Bg7 8. O-O
O-O 9. c4 Nc6 10. Nd5 Nxd5 11. cxd5 Ne7 12. Bg5 h6 13. Bh4 b6 14. Nc3 g5 15.
Bg3 Bb7 16. h3 Ng6 17. b4 Nf4 18. b5 a5 19. a4 Rc8 20. Ne2 Qd7 21. Nxf4 *
Position (FEN): 2r2rk1/1b1q1pb1/1p1p3p/pP1Pp1p1/P3PN2/3B2BP/5PP1/R2Q1RK1 b - - 0 21
Black to move.
Themes:  Middlegame  
Puzzle rating: 1139
Best move: exf4