1r2k1nr/pq2p1b1/n7/1Pp2b1p/2P1p1RP/N2Q4/1P1PNPBR/2B1K3 b k - 9 20
FEN state: 1r2k1nr/pq2p1b1/n7/1Pp2b1p/2P1p1RP/N2Q4/1P1PNPBR/2B1K3 b k - 9 20 ; Best move: a6b4
The current state of the chess board is: Black rook at b8, black king at e8, black knight at g8 and black rook at h8. Black pawn at a7, black queen at b7, black pawn at e7 and black bishop at g7. Black knight at a6. White pawn at b5, black pawn at c5, black bishop at f5 and black pawn at h5. White pawn at c4, black pawn at e4, white rook at g4 and white pawn at h4. White knight at a3 and white queen at d3. White pawn at b2, white pawn at d2, white knight at e2, white pawn at f2, white bishop at g2 and white rook at h2. White bishop at c1 and white king at e1. Black kingside is the only castle move available. Half move number is 9. Full move number is 20. Black to move.