r1bq1k2/pp1p1rp1/4p3/N1pB1p1p/1b3PP1/3P3P/P1P1P2R/RN1n1K2 w - - 4 18
FEN state: r1bq1k2/pp1p1rp1/4p3/N1pB1p1p/1b3PP1/3P3P/P1P1P2R/RN1n1K2 w - - 4 18 ; Best move: a5c4
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8 and black king at f8. Black pawn at a7, black pawn at b7, black pawn at d7, black rook at f7 and black pawn at g7. Black pawn at e6. White knight at a5, black pawn at c5, white bishop at d5, black pawn at f5 and black pawn at h5. Black bishop at b4, white pawn at f4 and white pawn at g4. White pawn at d3 and white pawn at h3. White pawn at a2, white pawn at c2, white pawn at e2 and white rook at h2. White rook at a1, white knight at b1, black knight at d1 and white king at f1. Both players have exhausted their castles. Half move number is 4. Full move number is 18. White to move.