@esamson How does Black lose exactly? Maybe you can give an example :P (hint: the kings can never cross the central ranks)
Interesting phenomenon in any case. It's exactly the type of position that engines are notoriously bad with. We humans can solve it trivially by doing a "bottom-up" search, but engines currently don't have that option outside of tablebases.. and their regular "top-down" search cannot nearly go deep enough so far..
and some helpmate positions (the last of which should be a helpmate in 5 but SF only finds it in 6): position fen 2k5/8/K7/8/8/8/8/7R b - - 0 1 position fen k7/8/2K5/8/8/8/8/6bB b - - 0 1 position fen bk6/8/K7/8/8/8/8/B7 b - - 0 1 position fen 8/8/8/8/k7/2R5/p5N1/7K b - - 0 1