Chess puzzle (Advantage)
Moves: 1. Nf3 Nf6 2. c4 e6 3. Nc3 c6 4. e4 g6 5. e5 Ng8 6. d4 d5 7. cxd5 cxd5 8. a3
Nc6 9. Bd3 Bg7 10. O-O Nge7 11. Bg5 Qb6 12. Bxe7 Kxe7 13. Na4 Qd8 14. Qd2 a6
15. Nc5 Bd7 16. Qg5+ Ke8 17. Qxd8+ Nxd8 18. Rfc1 b6 19. Nxa6 Bh6 20. Rc2 Ke7
21. Rc7 Nc6 22. Bb5 Rhd8 23. Nb4 *
Position (FEN): r2r4/2Rbkp1p/1pn1p1pb/1B1pP3/1N1P4/P4N2/1P3PPP/R5K1 b - - 8 23
Black to move.
Themes:  Middlegame  
Puzzle rating: 1500
Best move: Nxb4