Single Comment

An N-move rule is in general a good thing to have, but so is a clock, and historic rules usually don't specify anything about that either. There do exist variants without irreversible moves, though, (e.g. Shogi), and there it becomes very difficult to formulate a sensible rule for terminating no-progress games. Even in Chess the criterion is not irreversibility, but progress. (Castling does not reset the count.) Pawn advance can be seen as progress towards promotion, but if a promoting piece does not move irreversibly, moving it back and forth obviously would not. Variants that forbid perpetual chasing can often have very long stretches of checks without repeating, (which would be allowed) with which they could delay the loss. In combination with an N-move rule with any reasonable N this would make the ban on perpetual checking ineffective. And games that are theoretical wins could take thousands of moves to reach it, because every move that progresses towards a promotion is followed by some 100 checks before the losing side runs out of non-repeating checks.

A rule that I proposed to solve this was to limit the number of consecutive checks to, say, 3, unless you end the sequence with a capture. Then you can still make such sequences when they serve a purpose, but the delay you can achieve with the checks is limited. And checks+evasions can then be discounted for the N-move rule, without the total number of moves getting unacceptably high.

An alternative would be that the player that refuses a draw after a reasonable number of moves will lose when he does not manage to win within some unreasonably large number of moves. Then being forced to play the unreasonably large number of moves by a stubborn opponent who does not want to recognize the game-theoretical outcome is at least rewarded.