World Chess Championship matches have not had an on-board checkmate since 1929
en.wikipedia.org
en.wikipedia.org
I wonder what kind of malicious activity could be targetting that website?! Run of the mill scans?
I know at that level they're generally capable of identifying "probably a mate in 9 or so" and knocking off rather than wasting time. I wonder how much closer it gets.
What would the supposed benefit be?
BTW the “special case for looping endings” I think you’re talking about is to do with drawing by 3-fold repetition or the 50 move rule.
Their opponent could prolong the game by playing bad moves, too, but why would they? Once their opponent has mentally given up the game, making extra moves isn’t physically or mentally exhausting.