r2q2nr/p2pp1bp/1p3kp1/1Pn5/1RPPb2P/5p2/NBQ1PPP1/4KBNR w K - 1 20
FEN state: r2q2nr/p2pp1bp/1p3kp1/1Pn5/1RPPb2P/5p2/NBQ1PPP1/4KBNR w K - 1 20 ; Best move: d4c5
The current state of the chess board is: Black rook at a8, black queen at d8, black knight at g8 and black rook at h8. Black pawn at a7, black pawn at d7, black pawn at e7, black bishop at g7 and black pawn at h7. Black pawn at b6, black king at f6 and black pawn at g6. White pawn at b5 and black knight at c5. White rook at b4, white pawn at c4, white pawn at d4, black bishop at e4 and white pawn at h4. Black pawn at f3. White knight at a2, white bishop at b2, white queen at c2, white pawn at e2, white pawn at f2 and white pawn at g2. 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 1. Full move number is 20. White to move.