Interesting 4-men end-game

[hgm]

I just used fairygen to calculate an end-game from Chess with Different Armies, FIDE vs. Clobberers. Namely King + Rook vs. King + Waffle. (A waffle moves 1 step orthogonally, or jumps two steps diagonally, and acts as substitute for the Knight in the Clobberers army.)

One would expect the Waffle (W) to have approximately the same value as the Knight, both being short-range leapers with 8 move targets. And indeed, in many material combinations, the Waffle behaves like a regular minor. (E.g. being one waffle ahead in a Pawn-less end-game is not enough to win.) It has the distinct advantage over the Knight that KWWK is won where KNNK is a trivial draw.

But it turns out that KRKW is a sure win for the Rook. But an excessively slow one. It can takes up to 75 moves before you finally can force capture of the Waffle! That dwarfs KBNK or KQKR, which are the most difficult 4-men end-games with orthodox pieces.