Chess puzzle (Advantage)
Moves: 1. Nf3 d5 2. b3 e6 3. d4 Nc6 4. Bb2 Nf6 5. g3 Ne4 6. e3 Bb4+ 7. Nbd2 b6 8. a3
Bc3 9. Bxc3 Nxc3 10. Qc1 Bb7 11. a4 Nb4 12. Qb2 Ne4 13. Nxe4 dxe4 14. Nd2 Qd6
15. Bg2 Qc6 16. Nc4 f5 17. Ne5 Qxc2 18. Rb1 Qxb2 19. Rxb2 h5 20. O-O Nd3 *
Position (FEN): r3k2r/pbp3p1/1p2p3/4Np1p/P2Pp3/1P1nP1P1/1R3PBP/5RK1 w kq - 2 21
White to move.
Themes:  Middlegame  
Puzzle rating: 1133
Best move: Nxd3