r1b1kbn1/2q2pp1/4B3/pp1p3Q/3ppN2/KP1nP1P1/P1PP1P1P/RN1R4 w q - 0 21
FEN state: r1b1kbn1/2q2pp1/4B3/pp1p3Q/3ppN2/KP1nP1P1/P1PP1P1P/RN1R4 w q - 0 21 ; Best move: b3b4
The current state of the chess board is: Black rook at a8, black bishop at c8, black king at e8, black bishop at f8 and black knight at g8. Black queen at c7, black pawn at f7 and black pawn at g7. White bishop at e6. Black pawn at a5, black pawn at b5, black pawn at d5 and white queen at h5. Black pawn at d4, black pawn at e4 and white knight at f4. White king at a3, white pawn at b3, black knight at d3, white pawn at e3 and white pawn at g3. White pawn at a2, white pawn at c2, white pawn at d2, white pawn at f2 and white pawn at h2. White rook at a1, white knight at b1 and white rook at d1. Black queenside is the only castle move available. Half move number is 0. Full move number is 21. White to move.