Chess puzzle (Advantage)
Moves: 1. e4 c5 2. Nf3 Nc6 3. c4 e5 4. d3 d6 5. g3 h6 6. Bg2 g6 7. Be3 Bg7 8. Qd2 Nge7
9. Nc3 Be6 10. O-O Qd7 11. Nd5 g5 12. Rab1 Ng6 13. a3 O-O 14. b4 b6 15. Rb3 f5
16. exf5 Bxf5 17. Nc3 Rae8 18. Ne4 Nd4 19. Bxd4 exd4 20. Rfb1 Bg4 21. Ne1 Ne5
22. bxc5 dxc5 23. f4 *
Position (FEN): 4rrk1/p2q2b1/1p5p/2p1n1p1/2PpNPb1/PR1P2P1/3Q2BP/1R2N1K1 b - - 0 23
Black to move.
Themes:  Middlegame  
Puzzle rating: 1700
Best move: gxf4