r1bqk1r1/p2nbppp/2pp4/1P1n3P/3p1B2/NP3P1R/P2QP1P1/R3KBN1 b Q - 1 13
FEN state: r1bqk1r1/p2nbppp/2pp4/1P1n3P/3p1B2/NP3P1R/P2QP1P1/R3KBN1 b Q - 1 13 ; Best move: d5f4
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black king at e8 and black rook at g8. Black pawn at a7, black knight at d7, black bishop at e7, black pawn at f7, black pawn at g7 and black pawn at h7. Black pawn at c6 and black pawn at d6. White pawn at b5, black knight at d5 and white pawn at h5. Black pawn at d4 and white bishop at f4. White knight at a3, white pawn at b3, white pawn at f3 and white rook at h3. White pawn at a2, white queen at d2, white pawn at e2 and white pawn at g2. White rook at a1, 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 1. Full move number is 13. Black to move.