r1bkrq2/pp5p/1R3p1n/3ppPp1/Pb4P1/B1p4P/3PP1B1/RN2K1N1 w Q - 10 23
FEN state: r1bkrq2/pp5p/1R3p1n/3ppPp1/Pb4P1/B1p4P/3PP1B1/RN2K1N1 w Q - 10 23 ; Best move: b6b4
The current state of the chess board is: Black rook at a8, black bishop at c8, black king at d8, black rook at e8 and black queen at f8. Black pawn at a7, black pawn at b7 and black pawn at h7. White rook at b6, black pawn at f6 and black knight at h6. Black pawn at d5, black pawn at e5, white pawn at f5 and black pawn at g5. White pawn at a4, black bishop at b4 and white pawn at g4. White bishop at a3, black pawn at c3 and white pawn at h3. White pawn at d2, white pawn at e2 and white bishop at g2. White rook at a1, white knight at b1, white king at e1 and white knight at g1. White queenside is the only castle move available. Half move number is 10. Full move number is 23. White to move.