1r1k1b1r/ppp1pp1p/n2pb1pn/1q6/P3PP2/R1N3PN/1PPP3P/2B1KB1R w K - 0 10
FEN state: 1r1k1b1r/ppp1pp1p/n2pb1pn/1q6/P3PP2/R1N3PN/1PPP3P/2B1KB1R w K - 0 10 ; Best move: a4b5
The current state of the chess board is: Black rook at b8, black king at d8, black bishop at f8 and black rook at h8. Black pawn at a7, black pawn at b7, black pawn at c7, black pawn at e7, black pawn at f7 and black pawn at h7. Black knight at a6, black pawn at d6, black bishop at e6, black pawn at g6 and black knight at h6. Black queen at b5. White pawn at a4, white pawn at e4 and white pawn at f4. White rook at a3, white knight at c3, white pawn at g3 and white knight at h3. White pawn at b2, white pawn at c2, white pawn at d2 and white pawn at h2. White bishop 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 0. Full move number is 10. White to move.