3.3 Recreating the Same Position after a Pass (1)
After Black 3 takes the ko in Dia. 3-3-1, White has not even one ko
threat, so White 4 passes. Black cannot afford to connect this ko so he
also passes, leaving Dia. 3-3-2. If that is the end of the game, then
the black group on the lower side is alive. It cannot be removed even
though it has what in Japan would be considered a false eye at 'a' that
should cause it to be dead.
If moves that recreate a former position are allowed after two
consecutive passes, then White can recapture at 'a' and Black dies.
This is why some people propose to end the game with three passes. The
essential point is not that the game ends with three passes, but that
moves that recreate former positions are allowed after two passes. This
is where the problem lies.
In Dia. 3-3-3, after Black 3 takes the ko White has no ko threats. Black
is not going to connect at 'a' in Dia. 3-3-4, because then White could
recapture at 'b' and Black would have no ko threats. After Black 3,
accordingly, White and Black both pass and the game ends.
Under area rules there is no logical contradiction in ending the game
as in Dia. 3-3-4, but there is a problem about the points 'a' and 'b.'
Under area rules that are concerned only with stones (area rules I) 'a'
and 'b' do not count, and Black cannot occupy 'c' or 'd' either without
losing the stone to the left of 'b.' Under area rules that count both
stones and eyes (area rules II or III), 'a' to 'd' all count for Black.
Note that this difference between the two types of area rules is not
ascribable to the cutting bonus.
If exceptions to the rule forbidding recreation of the same position are
allowed after two consecutive passes, then after two passes White can
recapture at 'b.' Accordingly, Black will connect at 'a,' White will
capture at 'b,' Black will play at 'd,' and White will connect the ko.
So we are faced with the problem of whether to make an exception to
the super-ko rule after a pass. This is an important issue in settling
problems that might arise at the end of the game under both traditional
rules and new rules. The issue is also important in answering rules
theorists who propose to end the game with three passes.