As the ko rule in area rules, I would like to adopt the super-ko rule.
Then no repetitive cycles can occur. Even when a triple ko, round-robin
ko or eternal life arises, there will be no annulled games. This is the
place for a brief explanation of the super-ko rule.
The super-ko rule forbids playing a stone so as to create a position
(meaning the entire board position) that is identical to a position that
has already occurred some number of moves before (matching that previous
position on the entire board). This forces the game to keep progressing.
The board can never return to a previous state, so the game can never
degenerate into an endless cycle.
By way of an example, we can take the eternal life that starts with
Black 1 in Dia. 3-2-1. After the moves in Dia. 3-2-2, if Black captures
two white stones with 5 (Dia. 3-2-3), the position returns to Dia.
3-2-1. Black 5 is therefore prohibited by the super-ko rule. Black must
play a ko threat such as 5 in Dia. 3-2-4. After playing 5, Black can
capture with 7 in Dia. 3-2-5. The result differs from Dia. 3-2-1 because
of Black 5 and White 6.