1r1bk1nr/1bp2p2/2np3p/1P1Np3/4P1P1/1P2BP2/P3PKP1/1R3BNR b k - 4 20
FEN state: 1r1bk1nr/1bp2p2/2np3p/1P1Np3/4P1P1/1P2BP2/P3PKP1/1R3BNR b k - 4 20 ; Best move: c6d4
The current state of the chess board is: Black rook at b8, black bishop at d8, black king at e8, black knight at g8 and black rook at h8. Black bishop at b7, black pawn at c7 and black pawn at f7. Black knight at c6, black pawn at d6 and black pawn at h6. White pawn at b5, white knight at d5 and black pawn at e5. White pawn at e4 and white pawn at g4. White pawn at b3, white bishop at e3 and white pawn at f3. White pawn at a2, white pawn at e2, white king at f2 and white pawn at g2. White rook at b1, white bishop at f1, white knight at g1 and white rook at h1. Black kingside is the only castle move available. Half move number is 4. Full move number is 20. Black to move.