Technique on getting first capture in a ko

  Difficulty: Intermediate   Keywords: Life & Death, Ko

The basic technique is to throw-in first and avoid having to create a throw-in ko. It is a recurring technique in many life-and-death situations in games.

Getting the first capture in a ko is important, because the opponent will then have to find the first ko threat. This is usually worth some points in a ko of substantial value when adequate threats are limited. In an almighty ko capturing first can decide the ko, when there is no adequate threat on the board, especially early in the game.

The purpose of this page is to describe the basic technique on getting the first capture, and I will illustrate it through an example problem.

Example

[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.

Hopefully, the reader will find it useful.

See also


Author: unkx80


This is a copy of the living page "Technique on getting first capture in a ko" at Sensei's Library.
(OC) 2014 the Authors, published under the OpenContent License V1.0.
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