2b1kb1r/rq2pppp/2p5/pp2P3/1QpP1P2/6KN/nPP3Pn/RNB2R2 w k - 4 18
FEN state: 2b1kb1r/rq2pppp/2p5/pp2P3/1QpP1P2/6KN/nPP3Pn/RNB2R2 w k - 4 18 ; Best move: b4e1
The current state of the chess board is: Black bishop at c8, black king at e8, black bishop at f8 and black rook at h8. Black rook at a7, black queen at b7, black pawn at e7, black pawn at f7, black pawn at g7 and black pawn at h7. Black pawn at c6. Black pawn at a5, black pawn at b5 and white pawn at e5. White queen at b4, black pawn at c4, white pawn at d4 and white pawn at f4. White king at g3 and white knight at h3. Black knight at a2, white pawn at b2, white pawn at c2, white pawn at g2 and black knight at h2. White rook at a1, white knight at b1, white bishop at c1 and white rook at f1. Black kingside is the only castle move available. Half move number is 4. Full move number is 18. White to move.