r1bq1b1r/pp1k1p1p/n3p1pn/2p5/1P6/2NPPP2/P1PBN1PP/1R1QKB1R b K - 0 10
FEN state: r1bq1b1r/pp1k1p1p/n3p1pn/2p5/1P6/2NPPP2/P1PBN1PP/1R1QKB1R b K - 0 10 ; Best move: c5b4
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black bishop at f8 and black rook at h8. Black pawn at a7, black pawn at b7, black king at d7, black pawn at f7 and black pawn at h7. Black knight at a6, black pawn at e6, black pawn at g6 and black knight at h6. Black pawn at c5. White pawn at b4. White knight at c3, white pawn at d3, white pawn at e3 and white pawn at f3. White pawn at a2, white pawn at c2, white bishop at d2, white knight at e2, white pawn at g2 and white pawn at h2. White rook at b1, white queen at d1, 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 0. Full move number is 10. Black to move.