r3k1r1/1b2ppb1/1pn2P2/p1p4p/2p2PB1/NP5P/P1PP2q1/1RB1K2R w q - 3 21
FEN state: r3k1r1/1b2ppb1/1pn2P2/p1p4p/2p2PB1/NP5P/P1PP2q1/1RB1K2R w q - 3 21 ; Best move: c1b2
The current state of the chess board is: Black rook at a8, black king at e8 and black rook at g8. Black bishop at b7, black pawn at e7, black pawn at f7 and black bishop at g7. Black pawn at b6, black knight at c6 and white pawn at f6. Black pawn at a5, black pawn at c5 and black pawn at h5. Black pawn at c4, white pawn at f4 and white bishop at g4. White knight at a3, white pawn at b3 and white pawn at h3. White pawn at a2, white pawn at c2, white pawn at d2 and black queen at g2. White rook at b1, white bishop at c1, white king at e1 and white rook at h1. Black queenside is the only castle move available. Half move number is 3. Full move number is 21. White to move.