r1bq3k/1pp1n1br/p1np1p1p/1P2p1p1/4P1P1/2P2N1P/PNQP1P2/R1B1KB1R b KQ - 4 15
FEN state: r1bq3k/1pp1n1br/p1np1p1p/1P2p1p1/4P1P1/2P2N1P/PNQP1P2/R1B1KB1R b KQ - 4 15 ; Best move: a6b5
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8 and black king at h8. Black pawn at b7, black pawn at c7, black knight at e7, black bishop at g7 and black rook at h7. Black pawn at a6, black knight at c6, black pawn at d6, black pawn at f6 and black pawn at h6. White pawn at b5, black pawn at e5 and black pawn at g5. White pawn at e4 and white pawn at g4. White pawn at c3, white knight at f3 and white pawn at h3. White pawn at a2, white knight at b2, white queen at c2, white pawn at d2 and white pawn at f2. White rook at a1, white bishop at c1, white king at e1, white bishop at f1 and white rook at h1. White kingside and white queenside castles are available. Half move number is 4. Full move number is 15. Black to move.