Chess puzzle (Advantage)
Opening: Reti_Opening, Reti_Opening_Advance_Variation
Moves: 1. Nf3 d5 2. c4 d4 3. g3 c5 4. d3 b6 5. Bg2 Bb7 6. Nbd2 e6 7. O-O Nf6 8. a3 h6
9. b4 cxb4 10. Qa4+ Bc6 11. Qxb4 *
Position (FEN): rn1qkb1r/p4pp1/1pb1pn1p/8/1QPp4/P2P1NP1/3NPPBP/R1B2RK1 b kq - 0 11
Black to move.
Themes:  Middlegame  
Puzzle rating: 1066
Best move: Bxb4