Chess puzzle (Advantage)
Opening: Sicilian_Defense, Sicilian_Defense_Modern_Variations
Moves: 1. e4 c5 2. Nf3 d6 3. Nc3 Nc6 4. d4 cxd4 5. Nxd4 a6 6. Be2 e6 7. O-O Nf6 8. Bg5
Be7 9. f4 *
Position (FEN): r1bqk2r/1p2bppp/p1nppn2/6B1/3NPP2/2N5/PPP1B1PP/R2Q1RK1 b kq - 0 9
Black to move.
Themes:  Opening  
Puzzle rating: 1755
Best move: Qb6