r4b1r/p1p2n1p/bp1kppp1/nP3PN1/2BpPqP1/N2P4/P1P5/R1BK1Q2 b - - 4 21
FEN state: r4b1r/p1p2n1p/bp1kppp1/nP3PN1/2BpPqP1/N2P4/P1P5/R1BK1Q2 b - - 4 21 ; Best move: f4f1
The current state of the chess board is: Black rook at a8, black bishop at f8 and black rook at h8. Black pawn at a7, black pawn at c7, black knight at f7 and black pawn at h7. Black bishop at a6, black pawn at b6, black king at d6, black pawn at e6, black pawn at f6 and black pawn at g6. Black knight at a5, white pawn at b5, white pawn at f5 and white knight at g5. White bishop at c4, black pawn at d4, white pawn at e4, black queen at f4 and white pawn at g4. White knight at a3 and white pawn at d3. White pawn at a2 and white pawn at c2. White rook at a1, white bishop at c1, white king at d1 and white queen at f1. Both players have exhausted their castles. Half move number is 4. Full move number is 21. Black to move.