Chess puzzle (Checkmate)
Opening: Scandinavian_Defense, Scandinavian_Defense_Main_Line
Moves: 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. Bc4 Nf6 5. d3 c6 6. Bd2 Bg4 7. Nf3 e6 8. h3
Bh5 9. Nd5 Qd8 10. Nxf6+ Qxf6 11. Bc3 Bxf3 12. Qxf3 Qxf3 13. gxf3 Nd7 14. O-O-O
b5 15. Bb3 a5 16. a3 b4 17. axb4 axb4 18. Bd2 *
Position (FEN): r3kb1r/3n1ppp/2p1p3/8/1p6/1B1P1P1P/1PPB1P2/2KR3R b kq - 1 18
Black to move.
Themes:  Middlegame Back Rank Mate, Mate in 1 
Puzzle rating: 465
Best move: Ra1#