Technique on getting first capture in a ko

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  Difficulty: Beginner   Keywords: Life & Death, Ko

It is important to get first capture in a ko, because it will save one ko-threat. The purpose of this page is to describe a basic technique on getting the first capture, and I will illustrate it through an example problem.

[Diagram]

Problem

In this easy life-and-death problem, it looks like Black has two eyes. However, these eyes are a bit too close to each other. How can White exploit this?

[Diagram]

Black gets first capture

A possible exploitation is to first atari at W1, forcing B2, and then creates a throw-in ko at W3. If White wins this ko, then White can capture at a, rendering the eye at b false.

However, Black gets the first capture for this ko. Can White do better?

[Diagram]

White gets first capture

The answer is yes. Instead of making the atari on the two Black stones first, White can make the throw-in at W1 first. Then when B2 captures, W3 is a double atari. Now when Black plays at a to save the two stones, White gets the first capture at W1.



This basic technique, to throw-in first and avoiding having to create a throw-in ko, is a recurring technique in many life-and-death situations in games. Hopefully, the reader will find it useful.

--unkx80



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This is a copy of the living page "Technique on getting first capture in a ko" at Sensei's Library.
(OC) 2007 the Authors, published under the OpenContent License V1.0.
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