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Almost Fill
Path: LifeAndDeath   · Prev: Nakade   · Next: BasicDeathShapes
   

Almost fill

A key feature of life and death is the idea of almost filling the eye space of a group. This subject is closely related to nakade.

To almost fill means: to leave one liberty inside the eyespace.

An easy example:

[Diagram]
Diag.: Almost filled

White's eye space is almost filled with two stones. The circled point is the last liberty left inside the eyespace. It does not really matter whether the outside liberties are all filled or not. In this case they are, so White's group is in atari.


[Diagram]
Diag.: Almost filled

Here White has two outside liberties. The eyespace is still almost filled with two stones.



Dead shapes

If you manage to almost fill the eyespace of an enemy group with one of the following shapes, and there is no escape for that group, it dies (= will be captured). These shapes, and the reason why they kill, are explained in detail in nakade.

1. One stone

[Diagram]
Diag.: One stone


2. Two stones (chained)

[Diagram]
Diag.: Two stones


3. Three stones (chained), either in a straight line or bent.

[Diagram]
Diag.: straight 3


4a. Four stones in a square

[Diagram]
Diag.: square four


4b. Four stones in a farmers hat

[Diagram]
Diag.: farmer's hat


5a. Bulky five

[Diagram]
Diag.: bulky five


5a. Five in a cross

[Diagram]
Diag.: cross


6. Rabbitty six

[Diagram]
Diag.: rabbitty six


Alive shapes

All shapes other than the ones above, give life to a group, in the absence of cutting points. The smallest ones are:

1. Straight 4

[Diagram]
Diag.: straight 4


2. Bent 4

[Diagram]
Diag.: bent 4


Beware however of bent four in the corner.


Applications

You can go on and find all kinds of applications, by leaving more liberties inside the eyespace or creating cutting points.

Here is one:

[Diagram]
Diag.: straight 3, two liberties

There are three stones inside White's eyespace, but they don't almost fill it as there are two liberties left. If Black occupies either one of them, he has almost filled the eyespace with straight 4, which is a living shape. White of course should not occupy either of the inside liberties, since otherwise her eyespace is almost filled with straight three, a dead shape. Neither Black nor White will want to touch this position[1]. It is seki.



[1]: Actually, Black may play there, if all outside liberties are filled, as a ko threat. It is, however, a ko-threat losing points.


Authors:



Path: LifeAndDeath   · Prev: Nakade   · Next: BasicDeathShapes
This is a copy of the living page "Almost Fill" at Sensei's Library.
(C) the Authors, published under the OpenContent License V1.0.