Alternative ladders

    Keywords: Tactics

Note: The term "alternative ladders" is not an established Go term. For another interpretation of "alternative ladders", see double threat ladder maker.

Sometimes, it might be possible to atari a group in two different ways, such that both ataris lead to different ladders. The player will have to choose between the alternative ladders.

Example 1

This example is also known as parallel ladders.

[Diagram]

Choosing a good ladder

Here White has a choice of two ladders.

Because black+circle breaks just one of them, White must be careful. W1 and W3 are the correct way. Now Black's stones can't escape.

[Diagram]

Mistake

W1 here is a mistake, from the point of view of capturing Black.

[Diagram]

The ladder fails

Later on in the ladder B4 makes it impossible for White to continue.

[Diagram]

Bearing driving in mind

Moving black+circle closer along the diagonal does change things, White might then want to play W1, W3 and W5 here instead: a driving tesuji. It all depends on the direction of play whether capturing the two Black stones, or blighting black+circle on the bottom, is bigger.



Example 2

[Diagram]

Alternate ladders

In this example, Black has to choose from two alternate ladders, a or b. These ladders lead to different directions though.



See also


This is a copy of the living page "Alternative ladders" at Sensei's Library.
(OC) 2016 the Authors, published under the OpenContent License V1.0.
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