rnb4r/p4k2/1pp2p1n/1N1pqP1p/1PPbp1P1/4P2N/P2PB2P/BQR1K2R b K - 0 21
FEN state: rnb4r/p4k2/1pp2p1n/1N1pqP1p/1PPbp1P1/4P2N/P2PB2P/BQR1K2R b K - 0 21 ; Best move: d4a1
The current state of the chess board is: Black rook at a8, black knight at b8, black bishop at c8 and black rook at h8. Black pawn at a7 and black king at f7. Black pawn at b6, black pawn at c6, black pawn at f6 and black knight at h6. White knight at b5, black pawn at d5, black queen at e5, white pawn at f5 and black pawn at h5. White pawn at b4, white pawn at c4, black bishop at d4, black pawn at e4 and white pawn at g4. White pawn at e3 and white knight at h3. White pawn at a2, white pawn at d2, white bishop at e2 and white pawn at h2. White bishop at a1, white queen at b1, white rook at c1, white king at e1 and white rook at h1. White kingside is the only castle move available. Half move number is 0. Full move number is 21. Black to move.