2r1kb1r/p2b3p/2pp2pn/1p3p2/P1P1p1P1/N2P3N/1P2PQ1P/R1B1KB1R b k - 0 20
FEN state: 2r1kb1r/p2b3p/2pp2pn/1p3p2/P1P1p1P1/N2P3N/1P2PQ1P/R1B1KB1R b k - 0 20 ; Best move: b5b4
The current state of the chess board is: Black rook at c8, black king at e8, black bishop at f8 and black rook at h8. Black pawn at a7, black bishop at d7 and black pawn at h7. Black pawn at c6, black pawn at d6, black pawn at g6 and black knight at h6. Black pawn at b5 and black pawn at f5. White pawn at a4, white pawn at c4, black pawn at e4 and white pawn at g4. White knight at a3, white pawn at d3 and white knight at h3. White pawn at b2, white pawn at e2, white queen at f2 and white pawn at h2. White rook at a1, white bishop at c1, white king at e1, white bishop at f1 and white rook at h1. Black kingside is the only castle move available. Half move number is 0. Full move number is 20. Black to move.