1nbk2r1/1p2q3/1r1p1n1p/p3pPp1/1PN1B3/5NP1/PP1P1P1P/1RBK1QR1 b - - 4 21
FEN state: 1nbk2r1/1p2q3/1r1p1n1p/p3pPp1/1PN1B3/5NP1/PP1P1P1P/1RBK1QR1 b - - 4 21 ; Best move: b6b4
The current state of the chess board is: Black knight at b8, black bishop at c8, black king at d8 and black rook at g8. Black pawn at b7 and black queen at e7. Black rook at b6, black pawn at d6, black knight at f6 and black pawn at h6. Black pawn at a5, black pawn at e5, white pawn at f5 and black pawn at g5. White pawn at b4, white knight at c4 and white bishop at e4. White knight at f3 and white pawn at g3. White pawn at a2, white pawn at b2, white pawn at d2, white pawn at f2 and white pawn at h2. White rook at b1, white bishop at c1, white king at d1, white queen at f1 and white rook at g1. Both players have exhausted their castles. Half move number is 4. Full move number is 21. Black to move.