1nb1kbnr/1p1pqp1p/r5p1/p1P1p3/P1P4P/N2PPNP1/3K1PB1/R1BQ1R2 w k - 2 18
FEN state: 1nb1kbnr/1p1pqp1p/r5p1/p1P1p3/P1P4P/N2PPNP1/3K1PB1/R1BQ1R2 w k - 2 18 ; Best move: a3b5
The current state of the chess board is: Black knight at b8, black bishop at c8, black king at e8, black bishop at f8, black knight at g8 and black rook at h8. Black pawn at b7, black pawn at d7, black queen at e7, black pawn at f7 and black pawn at h7. Black rook at a6 and black pawn at g6. Black pawn at a5, white pawn at c5 and black pawn at e5. White pawn at a4, white pawn at c4 and white pawn at h4. White knight at a3, white pawn at d3, white pawn at e3, white knight at f3 and white pawn at g3. White king at d2, white pawn at f2 and white bishop at g2. White rook at a1, white bishop at c1, white queen at d1 and white rook at f1. Black kingside is the only castle move available. Half move number is 2. Full move number is 18. White to move.