Chess puzzle (Advantage)
Moves: 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. Qe2 Qe7 6. d3 Nf6 7. Bg5 Be6 8.
Nc3 Nbd7 9. O-O-O h6 10. Bh4 g5 11. Bg3 Bg7 12. Re1 O-O-O 13. d4 d5 14. Nb5 Kb8
15. Bxc7+ Ka8 16. Bxd8 Rxd8 17. Ne5 Rc8 18. Qe3 Qb4 19. a3 Qa5 20. b4 Qb6 21.
Qb3 *
Position (FEN): k1r5/pp1n1pb1/1q2bn1p/1N1pN1p1/1P1P4/PQ6/2P2PPP/2K1RB1R b - - 2 21
Black to move.
Themes:  Middlegame  
Puzzle rating: 1831
Best move: a6