Chess puzzle (Equality)
Moves: 1. d4 d5 2. c4 dxc4 3. Nc3 Nf6 4. e3 e5 5. d5 c6 6. Bxc4 Bb4 7. a3 Bxc3+ 8.
bxc3 cxd5 9. Bb5+ Nc6 10. Nf3 Qd6 11. O-O O-O 12. a4 a6 *
Position (FEN): r1b2rk1/1p3ppp/p1nq1n2/1B1pp3/P7/2P1PN2/5PPP/R1BQ1RK1 w - - 0 13
White to move.
Themes:  Middlegame  
Puzzle rating: 1620
Best move: Ba3