TalkChess.com

[Kevin Hearn]

disable null move and it should find the answer very quickly. The problem lies in lines like Kh6 Be5 Kg7 Bxf6 gxf6 +- where a) black might be evaluated as better by static eval (he is up a rook for a mere pawn, and passers are not readily evident) and b) null moves can continue to save the position. There is a null move verification search, but obviously it's not catching it all that quickly.

If you wanted to fix this specific position in the engine without weakening it too much you'd either need to work on the static eval to recognise the dead rook or make exceptions to the null move search - it currently has the requirement that the position must have nonpawn material for the side to move, you could try for instance changing that to having more than one piece for the side to move.