The preceding question about the final ko should be considered as an
instance of the more general question of reinforcing moves. In Dia. 2-6,
where Black still has more ko threats, he may claim that since he does
not have to connect at 1, he does not have to capture the white stone
by playing 2 either. This is essentially the question that arose in the
Go-Iwamoto game. For a further question, how should the three-stage ko
in Dia. 2-7-1 be resolved? When Black takes the ko at 1, White plays 2
in Dia. 2-7-2 to create a ko threat. When Black proceeds to capture at
3, White plays his ko threat at 4 and retakes the ko with 6. Black has
no ko threats. Can the game end as in Dia. 2-7-3 without White's having
to make any further reinforcing moves?