r1bqk2b/p1np3r/1pp2p1p/4B3/1PP1Pn2/P5P1/3PQP1N/RN3K1R w q - 5 20
FEN state: r1bqk2b/p1np3r/1pp2p1p/4B3/1PP1Pn2/P5P1/3PQP1N/RN3K1R w q - 5 20 ; Best move: e5f4
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 bishop at h8. Black pawn at a7, black knight at c7, black pawn at d7 and black rook at h7. Black pawn at b6, black pawn at c6, black pawn at f6 and black pawn at h6. White bishop at e5. White pawn at b4, white pawn at c4, white pawn at e4 and black knight at f4. White pawn at a3 and white pawn at g3. White pawn at d2, white queen at e2, white pawn at f2 and white knight at h2. White rook at a1, white knight at b1, white king at f1 and white rook at h1. Black queenside is the only castle move available. Half move number is 5. Full move number is 20. White to move.