rn2k1r1/q3bpp1/3p4/pbp3Pp/Pp5n/1P5N/2PPP2P/1RBQKR2 w q - 1 20
FEN state: rn2k1r1/q3bpp1/3p4/pbp3Pp/Pp5n/1P5N/2PPP2P/1RBQKR2 w q - 1 20 ; Best move: a4b5
The current state of the chess board is: Black rook at a8, black knight at b8, black king at e8 and black rook at g8. Black queen at a7, black bishop at e7, black pawn at f7 and black pawn at g7. Black pawn at d6. Black pawn at a5, black bishop at b5, black pawn at c5, white pawn at g5 and black pawn at h5. White pawn at a4, black pawn at b4 and black knight at h4. White pawn at b3 and white knight at h3. White pawn at c2, white pawn at d2, white pawn at e2 and white pawn at h2. White rook at b1, white bishop at c1, white queen at d1, white king at e1 and white rook at f1. Black queenside is the only castle move available. Half move number is 1. Full move number is 20. White to move.