r1q1k1r1/p1pp3p/1p3ppn/1b2p2P/1QB3P1/4PNn1/PP3P2/RNB1K2R b q - 0 21
FEN state: r1q1k1r1/p1pp3p/1p3ppn/1b2p2P/1QB3P1/4PNn1/PP3P2/RNB1K2R b q - 0 21 ; Best move: b5c4
The current state of the chess board is: Black rook at a8, black queen at c8, black king at e8 and black rook at g8. Black pawn at a7, black pawn at c7, black pawn at d7 and black pawn at h7. Black pawn at b6, black pawn at f6, black pawn at g6 and black knight at h6. Black bishop at b5, black pawn at e5 and white pawn at h5. White queen at b4, white bishop at c4 and white pawn at g4. White pawn at e3, white knight at f3 and black knight at g3. White pawn at a2, white pawn at b2 and white pawn at f2. White rook at a1, white knight at b1, white bishop at c1, white king at e1 and white rook at h1. Black queenside is the only castle move available. Half move number is 0. Full move number is 21. Black to move.