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4-4 point low approach low extension, standard joseki
  Difficulty: Intermediate   Keywords: Joseki

[Diagram]
Standard joseki.

This is the standard joseki mentioned in 4-4 point low approach low extension.

This page aims to give a deeper discussion to this joseki.


[Diagram]
Miai plays.

Assuming there is some white stone or structure, say at WC. We will say that W1 and B2 are miai. In fact, B2 is very big and gives the black corner a base.

(The main alternative to B2 is Black a in the centre. The use of this play is discussed at 4-4 point low approach low extension, standard joseki, pushing in the centre. See also [1] below.)



Losing the base in the corner

[Diagram]
Tenuki.

For black to tenuki when WC is played is not a good idea. W1 gains substantially in territory and sets up an attack. B2 or a is the correct play, but black has not gained much territory or influence in this move. For B2 to play at b is a dangerous choice.


[Diagram]
All territory gone.

After W1, W3, W5, black's territory is all gone and black becomes eyeless. There is an important caveat here: we assume that the ladder is good for white. However, white can always choose to play a ladder breaker somewhere in the lower right, so the danger still lurks.


[Diagram]
Tesuji.

If the ladder is good for black, then B2 and B4 is the tesuji to counter W1. Further, if white a, then black b, and the two white stones gets captured.


[Diagram]
Reference diagram.

This is a reference diagram to show why the direct capture of BC does not work.


[Diagram]
Not enough.

This line of resistance is still not enough. After B6, if white a, then black b, then is reverts to the previous diagram, where white is captured.


[Diagram]
Still not good enough.

The result of allowing black to capture the two white stones favours black.


[Diagram]
The real stuff.

The ladder which was mentioned earlier is this. W5 followed by W7 is a strong move. The crucial question is whether the ladder at a works after B8.


[Diagram]
Trick play.

Finally, a trick play by black if the ladder is not good for black. B1 is a trick play, and W2 is the correct move, and black gains nothing. W2 must not be played at W3, otherwise black will play B2, capturing three white stones, and there is no ladder to talk about.



[1] Addendum

[Diagram]
The attachment.

Here we discuss the exchange of B2 and W3, followed by tenuki.


[Diagram]
Black secures the base.

Later, it is possible to answer W1 with B2, securing the base. However, the exchange of BC and WC strengthens white, losing the possibility of any invasion in white's two space expansion on the top. Also, white gains significantly in the exchange of W1 and B2 (because if black plays at B1, black can aim at a to capture a white stone). So the price to pay for the tenuki is considerable.


[Diagram]
Invasion not possible.

The good thing is, the invasion at W1 is no longer possible. Black applies the B2, B4 tesuji mentioned above but this time it works without the precondition of a working ladder. The reason is, with BC, black can play at B8, and white is finished.



This is a copy of the living page "4-4 point low approach low extension, standard joseki" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.