1rb1k2r/1p1p1pb1/2p1qnp1/pB2p2p/1PPNn3/N1Q2P2/P2P2P1/1RB3KR w k - 4 20
FEN state: 1rb1k2r/1p1p1pb1/2p1qnp1/pB2p2p/1PPNn3/N1Q2P2/P2P2P1/1RB3KR w k - 4 20 ; Best move: d4e6
The current state of the chess board is: Black rook at b8, black bishop at c8, black king at e8 and black rook at h8. Black pawn at b7, black pawn at d7, black pawn at f7 and black bishop at g7. Black pawn at c6, black queen at e6, black knight at f6 and black pawn at g6. Black pawn at a5, white bishop at b5, black pawn at e5 and black pawn at h5. White pawn at b4, white pawn at c4, white knight at d4 and black knight at e4. White knight at a3, white queen at c3 and white pawn at f3. White pawn at a2, white pawn at d2 and white pawn at g2. White rook at b1, white bishop at c1, white king at g1 and white rook at h1. Black kingside is the only castle move available. Half move number is 4. Full move number is 20. White to move.