rn1qkb2/pbp1npp1/3p3r/1p2p1Np/8/2N1PPP1/PPPP3P/R1BQKBR1 w q - 4 10
FEN state: rn1qkb2/pbp1npp1/3p3r/1p2p1Np/8/2N1PPP1/PPPP3P/R1BQKBR1 w q - 4 10 ; Best move: f1b5
The current state of the chess board is: Black rook at a8, black knight at b8, black queen at d8, black king at e8 and black bishop at f8. Black pawn at a7, black bishop at b7, black pawn at c7, black knight at e7, black pawn at f7 and black pawn at g7. Black pawn at d6 and black rook at h6. Black pawn at b5, black pawn at e5, white knight at g5 and black pawn at h5. White knight at c3, white pawn at e3, white pawn at f3 and white pawn at g3. White pawn at a2, white pawn at b2, white pawn at c2, white pawn at d2 and white pawn at h2. White rook at a1, white bishop at c1, white queen at d1, white king at e1, white bishop at f1 and white rook at g1. Black queenside is the only castle move available. Half move number is 4. Full move number is 10. White to move.