Chess puzzle (Crushing)
Opening: Polish_Opening, Polish_Opening_Queens_Indian_Variation
Moves: 1. b4 e6 2. Bb2 Nf6 3. b5 b6 4. Nf3 a6 5. bxa6 Bxa6 6. d3 Bb4+ 7. c3 Bc5 8. d4
Bd6 9. Nbd2 c6 10. c4 Qc7 11. g3 O-O 12. Bg2 Bb7 13. O-O Be7 14. e3 d5 15. cxd5
cxd5 16. Qb3 Nc6 17. Rfc1 Qd8 18. a4 Na5 19. Qb5 *
Position (FEN): r2q1rk1/1b2bppp/1p2pn2/nQ1p4/P2P4/4PNP1/1B1N1PBP/R1R3K1 b - - 2 19
Black to move.
Themes:  Middlegame  
Puzzle rating: 1454
Best move: Ba6