Local Ko Threat

    Keywords: Ko, Go term

Japanese: "soba-kou", literally "next-to ko", for "ko (threat) (right) next to (the ko fight itself)."
Chinese: 本身劫

A local ko threat is a ko threat that cannot be ignored, because ignoring it makes winning the ko useless. This kind of threat should therefore often be played before any other kind.

[Diagram]

Example 1

In this diagram, Black is playing ko for the life of his group in the corner. Black has just captured the ko with BS. The point a is now a local ko threat for White. If Black ignores this and connects the ko, White will play b, killing the black group. So Black must play at b himself to avoid this. White can now retake the ko.

[Diagram]

Example 2

In this example, Black is fighting a ko for the life of the group. When WC takes the ko, we can see that Black has a local ko threat at a (atari two White stones).


For clear-cut examples of why you sometimes delay local threats, see loss-making threats.



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