rnb1k1nr/3p3p/pp4p1/2p1p3/4pP2/bN1P2PB/PPPQ3P/RNB1KR2 w Q - 0 13
FEN state: rnb1k1nr/3p3p/pp4p1/2p1p3/4pP2/bN1P2PB/PPPQ3P/RNB1KR2 w Q - 0 13 ; Best move: b1a3
The current state of the chess board is: Black rook at a8, black knight at b8, black bishop at c8, black king at e8, black knight at g8 and black rook at h8. Black pawn at d7 and black pawn at h7. Black pawn at a6, black pawn at b6 and black pawn at g6. Black pawn at c5 and black pawn at e5. Black pawn at e4 and white pawn at f4. Black bishop at a3, white knight at b3, white pawn at d3, white pawn at g3 and white bishop at h3. White pawn at a2, white pawn at b2, white pawn at c2, white queen at d2 and white pawn at h2. White rook at a1, white knight at b1, white bishop at c1, white king at e1 and white rook at f1. White queenside is the only castle move available. Half move number is 0. Full move number is 13. White to move.