I was discussing the 3-3 invasion joseki with a friend and he mentioned the following.


I've drawn this out in a diagram: is move #3 good for black? I was playing through this and I feel white can kill #3 and make a living group.

Click Here To Show Diagram Code

[go]$$B Moves 1 to 3
$$ --------------
$$ | . . . . . . .
$$ | . 3 . . . . .
$$ | . . 2 . . . .
$$ | . . . 1 . . .
$$ | . . . . . . .[/go]

There's a bit about this at http://senseis.xmp.net/?33PointInvasion%2FDiscussion

EDIT: Apologies for wrong link.

The link to Sensei's Library in the message above shows some variations that might occur. I'd like to point out some strategic flaws in the 2-2 point move. WHite invaded at the the 3-3 point presumably to reduce a moyo Black was threatening to build on the outside. The normal variations after W2 leave White sealed in the corner and Black strong on the outside. If Black was trying to make outside influence this may help Black. Playing the 2-2 point, though, seems to chase White into the area outside the corner so White severely reduced the corner area for Black and also spoiled the outside on one side or the other. This seems to give White a better result than when Black plays a standard joseki. Besides this there is the possibility that the black 2-2 stone will become a loss without compensation.

Also, the 2-2 can be a trick play when played under the 4-4 stone, resulting in black (assuming the invading stone is white) killing the white stone, but white getting very thick outside. I know it doesn't quite answer your question, but it is related.

Side comment, I expect there to be circumstances where the 4-4 side is so strong outside that the 2-2 will kill a 3-3 invasion, but can't think of a reasonable situation in which the 2-2 kills but the 2-5 doesn't.

Click Here To Show Diagram Code

[go]$$B Moves 1 to 3
$$ --------------
$$ | . . . . . . .
$$ | . . . . 3 . .
$$ | . . 2 . . . .
$$ | . . . 1 . . .
$$ | . . . . . . .[/go]

Jumping to making a placement before reducing eyespace is conventionally a mistake. Especially when this involves more or less tenuki-ing a 3-3 invasion.

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