Chess puzzle (Advantage)
Moves: 1. d4 d6 2. c4 g6 3. e4 Nf6 4. Nc3 Bg7 5. Nf3 O-O 6. Be2 Na6 7. O-O Bg4 8. h3
Bxf3 9. Bxf3 c5 10. d5 e6 11. Rb1 exd5 12. Nxd5 Re8 13. Re1 Nc7 14. b4 Nfxd5
15. cxd5 cxb4 16. Bb2 a5 17. Bxg7 Kxg7 18. Qd4+ Kg8 19. Qb6 Ne6 20. Qxb7 *
Position (FEN): r2qr1k1/1Q3p1p/3pn1p1/p2P4/1p2P3/5B1P/P4PP1/1R2R1K1 b - - 0 20
Black to move.
Themes:  Middlegame  
Puzzle rating: 2221
Best move: Nd4