r2Bkb1r/1bpp1pp1/6Pn/1pn1p3/p1QP3p/PPP1P3/3NP3/3RKBNR w K - 4 21
FEN state: r2Bkb1r/1bpp1pp1/6Pn/1pn1p3/p1QP3p/PPP1P3/3NP3/3RKBNR w K - 4 21 ; Best move: c4b5
The current state of the chess board is: Black rook at a8, white bishop at d8, black king at e8, black bishop at f8 and black rook at h8. Black bishop at b7, black pawn at c7, black pawn at d7, black pawn at f7 and black pawn at g7. White pawn at g6 and black knight at h6. Black pawn at b5, black knight at c5 and black pawn at e5. Black pawn at a4, white queen at c4, white pawn at d4 and black pawn at h4. White pawn at a3, white pawn at b3, white pawn at c3 and white pawn at e3. White knight at d2 and white pawn at e2. White rook at d1, white king at e1, white bishop at f1, white knight at g1 and white rook at h1. White kingside is the only castle move available. Half move number is 4. Full move number is 21. White to move.