Chess puzzle (Advantage)
Opening: Queens_Pawn_Game, Queens_Pawn_Game_Symmetrical_Variation
Moves: 1. d4 d5 2. Nf3 Nf6 3. a3 Nc6 4. h3 e6 5. e3 a6 6. Nc3 Be7 7. Bd3 O-O 8. O-O b5
9. e4 b4 10. axb4 Nxb4 11. e5 Nxd3 *
Position (FEN): r1bq1rk1/2p1bppp/p3pn2/3pP3/3P4/2Nn1N1P/1PP2PP1/R1BQ1RK1 w - - 0 12
White to move.
Themes:  Middlegame  
Puzzle rating: 1422
Best move: exf6