r1q1kbrn/p3p2p/n4p2/1bQ5/4PpPP/2PP1P2/PP6/2RK1BNR b q - 0 20
FEN state: r1q1kbrn/p3p2p/n4p2/1bQ5/4PpPP/2PP1P2/PP6/2RK1BNR b q - 0 20 ; Best move: a6c5
The current state of the chess board is: Black rook at a8, black queen at c8, black king at e8, black bishop at f8, black rook at g8 and black knight at h8. Black pawn at a7, black pawn at e7 and black pawn at h7. Black knight at a6 and black pawn at f6. Black bishop at b5 and white queen at c5. White pawn at e4, black pawn at f4, white pawn at g4 and white pawn at h4. White pawn at c3, white pawn at d3 and white pawn at f3. White pawn at a2 and white pawn at b2. White rook at c1, white king at d1, white bishop at f1, white knight at g1 and white rook at h1. Black queenside is the only castle move available. Half move number is 0. Full move number is 20. Black to move.