r2qkNn1/3bp3/npp3p1/pP5r/P1P2P2/3P3P/1BK1P1b1/RNQ4R b q - 0 21
FEN state: r2qkNn1/3bp3/npp3p1/pP5r/P1P2P2/3P3P/1BK1P1b1/RNQ4R b q - 0 21 ; Best move: a6b4
The current state of the chess board is: Black rook at a8, black queen at d8, black king at e8, white knight at f8 and black knight at g8. Black bishop at d7 and black pawn at e7. Black knight at a6, black pawn at b6, black pawn at c6 and black pawn at g6. Black pawn at a5, white pawn at b5 and black rook at h5. White pawn at a4, white pawn at c4 and white pawn at f4. White pawn at d3 and white pawn at h3. White bishop at b2, white king at c2, white pawn at e2 and black bishop at g2. White rook at a1, white knight at b1, white queen at c1 and white rook at h1. Black queenside is the only castle move available. Half move number is 0. Full move number is 21. Black to move.