r2qkb2/1ppb1ppr/n2p3n/p2p3p/PP5P/2N1PP2/2P2KPR/R1BQ1BN1 b q - 0 10
FEN state: r2qkb2/1ppb1ppr/n2p3n/p2p3p/PP5P/2N1PP2/2P2KPR/R1BQ1BN1 b q - 0 10 ; Best move: d8f6
The current state of the chess board is: Black rook at a8, black queen at d8, black king at e8 and black bishop at f8. Black pawn at b7, black pawn at c7, black bishop at d7, black pawn at f7, black pawn at g7 and black rook at h7. Black knight at a6, black pawn at d6 and black knight at h6. Black pawn at a5, black pawn at d5 and black pawn at h5. White pawn at a4, white pawn at b4 and white pawn at h4. White knight at c3, white pawn at e3 and white pawn at f3. White pawn at c2, white king at f2, white pawn at g2 and white rook at h2. White rook at a1, white bishop at c1, white queen at d1, white bishop at f1 and white knight at g1. Black queenside is the only castle move available. Half move number is 0. Full move number is 10. Black to move.