r3qb1r/p1pkpppp/2np4/1P3n2/3P4/PQ2BN1b/1P2PPPP/RN2KB1R b K - 4 10
FEN state: r3qb1r/p1pkpppp/2np4/1P3n2/3P4/PQ2BN1b/1P2PPPP/RN2KB1R b K - 4 10 ; Best move: c6a5
The current state of the chess board is: Black rook at a8, black queen at e8, black bishop at f8 and black rook at h8. Black pawn at a7, black pawn at c7, black king at d7, black pawn at e7, black pawn at f7, black pawn at g7 and black pawn at h7. Black knight at c6 and black pawn at d6. White pawn at b5 and black knight at f5. White pawn at d4. White pawn at a3, white queen at b3, white bishop at e3, white knight at f3 and black bishop at h3. White pawn at b2, white pawn at e2, white pawn at f2, white pawn at g2 and white pawn at h2. White rook at a1, white knight at b1, white king at e1, white bishop at f1 and white rook at h1. White kingside is the only castle move available. Half move number is 4. Full move number is 10. Black to move.