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Invasion of third line three space extension
Path: ThreeSpaceExtensionInvasions   · Prev:   · Next: HighInvasionOfFourthLineThreeSpaceExtension
    Keywords: MiddleGame, Joseki

Table of contents Table of diagrams
Black's options
White invasion
Response
Drawing back
Cut or Draw Back?
Cutting continued
Cutting continued
Drawing out
black makes two walls, white escapes
white more submissive ?
knight move variation 1
knight move variation 2

Standard replies to 3 space extension invasion


[Diagram]
Black's options

bobulatorm: a, b and c are all standard responses, depending on surrounding board positions. b is a strong attack when B has supporting forces nearby. c is a slightly weaker attack, and a is only to be played as a purely defensive attatchment.




Lower attachment

[Diagram]
White invasion

Icepick: The most common response I see (as a DDK) is a.



[Diagram]
Response

W2 can be on either side, depending on the rest of the context. At this point, Black can either draw back at a, or cut at b.



[Diagram]
Drawing back

Peaceful, but Black is separated

HolIgor: This variation is considered bad for Black as one of the black stones remains in a silly position.

dnerra: I would like to support HolIgor's point very strongly. This is result is a big disaster (in fact, so big, that I almost used all-caps...) for Black, unless he wanted to sacrifice the stone on the right from the very beginning.



[Diagram]
Cut or Draw Back?

White can now cut back at a or draw out at b.

dnerra The cut is only possible if there is help from nearby stones.



[Diagram]
Cutting continued

Black sacrifices to get outside influence, while White gets some territory.

Velobici: This line of play appears to be horrible for Black. Black started with a two stone to one stone advantage. Black has sacrificed four stones. White is out to the left with a nice position. The White cut at a remains a danger for Black.

HolIgor: Acceptable. Usually B4 and B6 are not played. They are ko-threats. White's aji is not good. The roots of the problem are in the previous moves. How did it happen that Black had a hole in the middle? Why did Black choose to play on the second line instead of jumping out and starting a running fight? Everything depends on the environment. There are situations where this line of play is OK for Black. Black gets compensation in the form of outside influence.

dnerra This diagram leaves me very confused. I cannot come up with any surrounding conditions where this sequence makes sense. I think the author of it may have mixed it up with the following sequence, which is sometimes correct:


[Diagram]
Cutting continued

Here the point of adding B2 and B4 to the sacrifice is that additionally to B6, also B0 becomes sente.


[Diagram]
Drawing out

dnerra: W1 is usually played at B2.




Diagonal attack


diagonal attack attempts:

[Diagram]
black makes two walls, white escapes

still black needs to defend at a


[Diagram]
white more submissive ?

or


[Diagram]
knight move variation 1



[Diagram]
knight move variation 2




Weaker attack




Path: ThreeSpaceExtensionInvasions   · Prev:   · Next: HighInvasionOfFourthLineThreeSpaceExtension
This is a copy of the living page "Invasion of third line three space extension" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.