Chess puzzle (Advantage)
Opening: Blackmar-Diemer_Gambit, Blackmar-Diemer_Gambit_Ryder_Gambit
Moves: 1. d4 Nf6 2. Nc3 d5 3. e4 dxe4 4. f3 exf3 5. Qxf3 e6 6. Bg5 Be7 7. O-O-O Nd5 8.
Bxe7 Qxe7 9. Nxd5 exd5 10. Qxd5 Nc6 11. Nf3 Be6 12. Qb5 O-O-O 13. a3 Rd5 14.
Qd3 Bf5 15. Qd2 Rhd8 16. Bc4 Ra5 17. Rhe1 Qd6 18. c3 Rxa3 *
Position (FEN): 2kr4/ppp2ppp/2nq4/5b2/2BP4/r1P2N2/1P1Q2PP/2KRR3 w - - 0 19
White to move.
Themes:  Middlegame  
Puzzle rating: 1454
Best move: bxa3