1r1q1bnr/4k1pp/pn2p2B/Pppp2NP/QPP2p2/4NPP1/4P3/1R2KB1R b K - 1 21
FEN state: 1r1q1bnr/4k1pp/pn2p2B/Pppp2NP/QPP2p2/4NPP1/4P3/1R2KB1R b K - 1 21 ; Best move: b6a4
The current state of the chess board is: Black rook at b8, black queen at d8, black bishop at f8, black knight at g8 and black rook at h8. Black king at e7, black pawn at g7 and black pawn at h7. Black pawn at a6, black knight at b6, black pawn at e6 and white bishop at h6. White pawn at a5, black pawn at b5, black pawn at c5, black pawn at d5, white knight at g5 and white pawn at h5. White queen at a4, white pawn at b4, white pawn at c4 and black pawn at f4. White knight at e3, white pawn at f3 and white pawn at g3. White pawn at e2. White rook 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 1. Full move number is 21. Black to move.