r4r2/q1p1b1p1/Q2pp1k1/1p5p/pP1P1B1P/2P2P2/P3Pn2/RN2KBN1 w Q - 2 21
FEN state: r4r2/q1p1b1p1/Q2pp1k1/1p5p/pP1P1B1P/2P2P2/P3Pn2/RN2KBN1 w Q - 2 21 ; Best move: a6a7
The current state of the chess board is: Black rook at a8 and black rook at f8. Black queen at a7, black pawn at c7, black bishop at e7 and black pawn at g7. White queen at a6, black pawn at d6, black pawn at e6 and black king at g6. Black pawn at b5 and black pawn at h5. Black pawn at a4, white pawn at b4, white pawn at d4, white bishop at f4 and white pawn at h4. White pawn at c3 and white pawn at f3. White pawn at a2, white pawn at e2 and black knight at f2. White rook at a1, white knight at b1, white king at e1, white bishop at f1 and white knight at g1. White queenside is the only castle move available. Half move number is 2. Full move number is 21. White to move.