rn1k1b1r/pbq4p/3np1p1/2p2p2/PBBpP1PP/R7/1PK2P2/2N3NR b - - 4 20
FEN state: rn1k1b1r/pbq4p/3np1p1/2p2p2/PBBpP1PP/R7/1PK2P2/2N3NR b - - 4 20 ; Best move: c5b4
The current state of the chess board is: Black rook at a8, black knight at b8, black king at d8, black bishop at f8 and black rook at h8. Black pawn at a7, black bishop at b7, black queen at c7 and black pawn at h7. Black knight at d6, black pawn at e6 and black pawn at g6. Black pawn at c5 and black pawn at f5. White pawn at a4, white bishop at b4, white bishop at c4, black pawn at d4, white pawn at e4, white pawn at g4 and white pawn at h4. White rook at a3. White pawn at b2, white king at c2 and white pawn at f2. White knight at c1, white knight at g1 and white rook at h1. Both players have exhausted their castles. Half move number is 4. Full move number is 20. Black to move.