Chess puzzle (Advantage)
Moves: 1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Nd2 e6 5. f3 Nc6 6. c3 Bd6 7. Bxd6 cxd6 8. g4
Bg6 9. h4 h6 10. Qb3 Qc7 11. Ne2 Nd7 12. Nf4 Bh7 13. Bd3 Bxd3 14. Nxd3 Na5 15.
Qb5 a6 16. Qa4 b5 17. Qc2 Nc4 18. Nxc4 dxc4 19. Nb4 a5 20. Qg2 *
Position (FEN): r3k2r/2qn1pp1/3pp2p/pp6/1NpP2PP/2P1PP2/PP4Q1/R3K2R b KQkq - 1 20
Black to move.
Themes:  Middlegame  
Puzzle rating: 1070
Best move: axb4