H. G. Muller wrote on Fri, Oct 5, 2018 07:43 PM UTC:
Oh, sorry, I had overlooked the 10x8 part of your question, and posted the numbers for 8x8. I now corrected that in the previous post. It means the worst-case mate is slightly longer, 27 moves instead of 23. Whether checkmate can be forced by a certain group of pieces is usually dependent only on the smallest dimension of the board, but the duration also depends on the large dimension.
It is an interesting question whether the Modern Elephants would lose their mating potential on a large-enough board. The pair of them would be able to keep up with the bare King when the latter tries to run away, but would than have to leave their own King behind. But the pair has a reasonable 'confining power', so perhaps they can hinder the bare King enough once this runs into an edge to let the other King approach before the bare one again flees to yet another corner.
Oh, sorry, I had overlooked the 10x8 part of your question, and posted the numbers for 8x8. I now corrected that in the previous post. It means the worst-case mate is slightly longer, 27 moves instead of 23. Whether checkmate can be forced by a certain group of pieces is usually dependent only on the smallest dimension of the board, but the duration also depends on the large dimension.
It is an interesting question whether the Modern Elephants would lose their mating potential on a large-enough board. The pair of them would be able to keep up with the bare King when the latter tries to run away, but would than have to leave their own King behind. But the pair has a reasonable 'confining power', so perhaps they can hinder the bare King enough once this runs into an edge to let the other King approach before the bare one again flees to yet another corner.