r3k3/p6r/N1nPp1p1/1p6/q3Pn1p/2P4P/P4PPR/R1K2BN1 b q - 0 21
FEN state: r3k3/p6r/N1nPp1p1/1p6/q3Pn1p/2P4P/P4PPR/R1K2BN1 b q - 0 21 ; Best move: a4a6
The current state of the chess board is: Black rook at a8 and black king at e8. Black pawn at a7 and black rook at h7. White knight at a6, black knight at c6, white pawn at d6, black pawn at e6 and black pawn at g6. Black pawn at b5. Black queen at a4, white pawn at e4, black knight at f4 and black pawn at h4. White pawn at c3 and white pawn at h3. White pawn at a2, white pawn at f2, white pawn at g2 and white rook at h2. White rook at a1, white king at c1, white bishop at f1 and white knight at g1. Black queenside is the only castle move available. Half move number is 0. Full move number is 21. Black to move.