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SecondCourseOnKo
ForcingAndInitiative

Referenced by
FindingAKo

 

Threatening a ko
Path: ForcingAndInitiative   · Prev: LadderBreaker   · Next: TakingSenteInAKo
Path: SecondCourseOnKo   · Prev: IfYouDonTLikeKoDonTPlayGo   · Next: TakingSenteInAKo

  Difficulty: Advanced   Keywords: Ko

A player with a clear advantage in ko threats may be able to take advantage of that situation. It can for example transform sequences that would be unreasonable for Black to follow, into sequences that would be unreasonable for White. Therefore the mere threat of losing a ko fight can have a forcing effect on the opponent.


There is a corresponding theoretical idea of ko master.


[Diagram]

(Sebastian:) Here's an example from the Igowalker site (20-bango Game #5). The description says: "Black ... can threaten a ko for everything with the kosumi on the first line." But why should White agree to play ko for everything? Can he not simply play at a? Then it would only be for the single white stone.

RafaelCaetano: The Black kosumi doesn't start the ko, it _threatens_ to start it. ;-) That is, if White plays elsewhere then Black can start the ko at b (and it's too late for White a). But yes, if White immediately answers at a, Black b catches at most one stone.

HolIgor: Normally Black will play below b but the option with B1 is open. The move at b can serve a different cause, as a yose move threatening to jump further to the south.

That example seems out of context, though. In that position Black will usually play below b, not B1. But you get the idea: the ko-threatening move should have another purpose besides the ko.



Path: ForcingAndInitiative   · Prev: LadderBreaker   · Next: TakingSenteInAKo
Path: SecondCourseOnKo   · Prev: IfYouDonTLikeKoDonTPlayGo   · Next: TakingSenteInAKo

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