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Eye by Exhaustion
Path: EyesCollection   · Prev: GroupWithOnlyHalfEyes   · Next:
    Keywords: Life & Death, Go term

Tamsin's term for the eye-making technique used in the following sample problem from the Korean Baduk Academy (on [ext] http://www.gobase.org/):

[Diagram]
Basic situation

[Diagram]
White's stones are too "exhausted" to move



And now White is unable to set up false eye-making throw-ins by playing either side of the WS stones, because that would be self-capture.[1] It seems to my mind that both the white stones are too "exhausted" to go one step further.


[1] Correct me if I'm wrong, but I believe that self-capture is legal under Ing Rules, in which case the Eye By Exhaustion method would fail.

Dieter: It doesn't fail. Rules have seldom effect on life and death issues and shapes.

Tamsin: Ah, yes, of course, because Black still has sente after White captures herself. But the status of this example does become slightly unsettled under Ing Rules, because White can use self-capture as a ko threat:

[Diagram]
White's ko threat using self-capture

If Black now plays tenuki to win the ko, White can throw-in at W1, killing Black's group.

mgoetze: But the number of ko threats stays the same... under Japanese rules there are also ko threats against this group, and they are mutually exclusive with the "additional" ko threats provided by rules allowing suicide:


[Diagram]
Ko Threats...

Threatening at a eliminates the threat at b, threatening at c eliminates the threat at d.

Tamsin: Yup, indeed. Two contrasting ways to the same end.

Andrew Grant: But sometimes there is a difference.


[Diagram]
No Threats...

In this position Black has no threats under Japanese rules but still two at a and b under Chinese rules.



unkx80: This page reminded me of yet another (famous) problem. See RTG Problem 11.



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This is a copy of the living page "Eye by Exhaustion" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.