Chess puzzle (Advantage)
Opening: Kings_Indian_Defense, Kings_Indian_Defense_Orthodox_Variation
Moves: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 c5 7. dxc5 dxc5 8. O-O
Nc6 9. Be3 b6 10. Qa4 Bb7 11. Rfd1 Qc8 12. h3 e6 13. Bf4 Nb4 14. Bd6 Rd8 15. e5
Bc6 16. Qb3 a5 17. a3 *
Position (FEN): r1qr2k1/5pbp/1pbBpnp1/p1p1P3/1nP5/PQN2N1P/1P2BPP1/R2R2K1 b - - 0 17
Black to move.
Themes:  Middlegame  
Puzzle rating: 1649
Best move: a4