r1bq1b1r/npp1k1p1/pQ1pp2p/5p2/1PP2P1P/N4NP1/P2PBP2/R1B1K1R1 w Q - 0 18
FEN state: r1bq1b1r/npp1k1p1/pQ1pp2p/5p2/1PP2P1P/N4NP1/P2PBP2/R1B1K1R1 w Q - 0 18 ; Best move: b6e3
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black bishop at f8 and black rook at h8. Black knight at a7, black pawn at b7, black pawn at c7, black king at e7 and black pawn at g7. Black pawn at a6, white queen at b6, black pawn at d6, black pawn at e6 and black pawn at h6. Black pawn at f5. White pawn at b4, white pawn at c4, white pawn at f4 and white pawn at h4. White knight at a3, white knight at f3 and white pawn at g3. White pawn at a2, white pawn at d2, white bishop at e2 and white pawn at f2. White rook at a1, white bishop at c1, white king at e1 and white rook at g1. White queenside is the only castle move available. Half move number is 0. Full move number is 18. White to move.