1r3bnr/pb1p1kpp/1pp5/q4p2/1PPPpP2/4P1PP/3NNB2/2R1KB1R w K - 5 20
FEN state: 1r3bnr/pb1p1kpp/1pp5/q4p2/1PPPpP2/4P1PP/3NNB2/2R1KB1R w K - 5 20 ; Best move: b4a5
The current state of the chess board is: Black rook at b8, black bishop at f8, black knight at g8 and black rook at h8. Black pawn at a7, black bishop at b7, black pawn at d7, black king at f7, black pawn at g7 and black pawn at h7. Black pawn at b6 and black pawn at c6. Black queen at a5 and black pawn at f5. White pawn at b4, white pawn at c4, white pawn at d4, black pawn at e4 and white pawn at f4. White pawn at e3, white pawn at g3 and white pawn at h3. White knight at d2, white knight at e2 and white bishop at f2. White rook at c1, 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 5. Full move number is 20. White to move.