Chess puzzle (Advantage)
Moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5 6. Bb5+ c6 7. dxc6 Nxc6 8.
Bc4 Be6 9. Bxe6 fxe6 10. Nxe6 Qd6 11. Nxf8 Rxf8 12. Nc3 a6 13. d3 O-O-O 14. O-O
h5 15. Bg5 Nd4 16. Ne4 Qc6 17. c3 Ne6 18. Bxf6 gxf6 19. Qxh5 Nf4 20. Qf5+ Kb8
21. d4 *
Position (FEN): 1k1r1r2/1p6/p1q2p2/4pQ2/3PNn2/2P5/PP3PPP/R4RK1 b - - 0 21
Black to move.
Themes:  Middlegame  
Puzzle rating: 1900
Best move: Rg8