Chess puzzle (Advantage)
Opening: Sicilian_Defense, Sicilian_Defense_Najdorf_Variation
Moves: 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nf5 Bxf5 8.
exf5 Be7 9. Bd3 Qb6 10. Qe2 O-O 11. Be3 *
Position (FEN): rn3rk1/1p2bppp/pq1p1n2/4pP2/8/2NBBP2/PPP1Q1PP/R3K2R b KQ - 6 11
Black to move.
Themes:  Middlegame  
Puzzle rating: 851
Best move: Qxb2