Chess puzzle (Advantage)
Opening: Slav_Defense, Slav_Defense_Chameleon_Variation
Moves: 1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. Nf3 a6 5. Bf4 Bf5 6. e3 e6 7. Nh4 Bg4 8. f3 Bh5
9. g4 Nxg4 10. fxg4 Qxh4+ 11. Kd2 Qxg4 12. Qxg4 *
Position (FEN): rn2kb1r/1p3ppp/p1p1p3/3p3b/2PP1BQ1/2N1P3/PP1K3P/R4B1R b kq - 0 12
Black to move.
Themes:  Middlegame  
Puzzle rating: 840
Best move: Bxg4