4-4 point 3-3 invasion joseki, hane inside cut
I guess I've seen this one before. I think he's trying to trick White into ; upon which
and
shut in her stones and make considerable thickness.
DJ: Not only that, a and b are sente for Black. I have created a page for this move as played by top pros. See below for a reference.
So I think White has to resist with . Then
sets up a double threat ladder maker.
This is a line of play that comes to mind. Depends on the ladder at a, but Black can sacrifice the stones, can't he ? Fairly complicated ...
Interesting variation, Dieter. I think that if the ladder works for White, this is good enough for her.
If Black is going to sacrifice the stones, he'd better not play at in your diagram (the marked point here), because this stone is going to be worthless once White has captured. It would be better to play at
here immediately; or perhaps Black a- White b -
-
. Still the result seems good for White.
But what can White do if the ladder does not work for her? The variation shown by Dieter is clearly bad for her in that case. My first intuition was to play at without the atari at a, leading to this variation.
I do however get the impression that this is good for Black: because the three white stones have only two liberties, White b is not sente, and White will have to play one of the circled points to use the aji of these stones.
I do not however see any other good options for White either, so when the ladder works for Black, only the 'Tricked' diagram and this diagram remain for White. Either that, or I have missed something.
If I have missed something, it seems that is the only move we haven't discussed yet.
seems like the natural answer, after which
and
follow.
This shows the follow-up from the previous diagram. White is locked up in the corner, but the marked stone still has quite some aji. Exchanging White a for Black b would decrease this aji.
-- Andre Engels
I like Andre's . It has the feeling of a true refutation of a trick move. One question is whether Black can resist more strongly with
than in the original diagram. Considering only the corner it does not seem possible. However, there may be a problem...
Remembering that the premise behind the 3-3 invasion is that Black has already played on the outside, can White afford to fight hard here or not? Black a now leaves White without two eyes.
Therefore, after , White turns back to
. However, after
it does not look like Black is going to able to contain White.
How about ? This move aims at the cutting point at a. Black cannot take the white stone on the left.
The "only" continuation would be ,
. Then
is an attempt to control
, as well as defending the cut. But
cuts there anyway as this brings the aji of
back to life. As I see it - Black is in trouble.
As found through Jansteen's GoBase. Which means my "new" move isn't a new move after all. Hm... Should I be happy or sad?
dnerra: Be happy, Goran! :) I have another option to discuss:
Could this be good enough sometimes? White is more confined than usual, but Black will have to add one more stone to take off.
(Anyway, Goran's move at a definitely looks more stylish!:)
Phlegmatic If the ladder works for White, this surely makes a very poor choice for Black here?
Charles The cut is considered a trick play. It has been seen in pro play, though. It was discussed in an old Go World (reference, someone?).
DJ: Well, yes, I happen to have that Go World: n. 19, June 1980; this move is discussed to some extent, as it was played by Otake (then Meijin) against Sato Masaharu (then 7 dan), in the quarter-final of the third stage of the 4th Kisei.
I have written a page with a short report of that discussion. I decided not to add it here for reasons of space.
A very good suggestion. The value of a sacrifice depends on the wholeboard position. When Black takes the stone, his shape is much stronger (naturally ). Black a threatens the corner with ko while White a ends in gote. Therefore Black will most likely get to play a in sente.
In this diagram or
are double sente plays and this situation is likely to be played out fairly early. White is left with a as an endgame move since Black a can be ignored. Note that if
is one point lower, Black a is sente.