Playing against sanrensei
It is fairly customary for Black to use the one-space pincer against a white approach to a 4-4 stone, in the sanrensei formation. Normally, White will enter the corner. and Black will gain magnificent thickness, a result which in my eyes is very good for Black.
Therefore, instead of doing what Black wants, it is possible to play as a double kakari.[1]
After , both Black a and Black b result in White getting a base inside Black's sanrensei:
Therefore, if Black wants to keep his framework, he should refrain from attaching:
Both a and b are seen in professional play these days.
SnotNose: I recall seeing this as a possible continuation (I may have a move or two wrong). I think I saw it in Making Good Shape by Bozulich. The idea is to sacrifice the two black stones in the corner so as to build a wall on the outside. There may be circumstances where this is appropriate, rather than making the bad shape of the previous diagram and leaving bad aji for White to mess with inside Black's moyo. However, this is a large corner for White. Maybe in the book the context was slighly different.
It is wrong for Black to attach against the second kakari stone as shown.
On top of that, White has the cut at a and the aji at 'b' to look forward to.
- FlorisBarthel?
[1]
Charles Matthews I'm having some difficulty verifying what is said here. I haven't yet found any pro games exactly matching the first diagram.
Just looking at the upper right (including ) this has happened a couple of times in high-level games, at the end of the sequence proposed in Variation 1.
There are games where the Variation 1 sequence is played, without . In that case, I suppose, White is more interested in playing later at a: so may avoid playing
.
Floris Barthel? You beat me to posting that ^_^
Big oyose continuation
Just as a sidenote to this variation, black has a HUGE endgame concerning this position but should not be played inmediately as it removes the aji of the two stones.
Dieter: Aha ! I can see Guo Juan is consistent in her teaching ...
FlorisBarthel?: Did she teach you this too? :)
Charles Well, I had figured out that this is a Guo Juan lesson: she played this joseki against Rui Naiwei in 2001, for one thing.
Anything that gets posted here is supposed to be discussed, though. We haven't really started on whole-board opening theory.
Fhayashi - I'd more likely play this as black. Any comments?
unkx80: Generally speaking this is okay. See Variation 3 above.
How does this look to you? Do you think this is too good for black? There must be a reason that has been the most common choice among pros. Well, white has just made territory in sente. And maybe that black wall isn't as thick as you think. You don't have to play this way, but at least try to appreciate it. In go you can sometimes give your opponent what he wants. -Jesse
SnotNose: This is okay but Black and White should be aware of the weaknesses in the shapes. When appropriate, White can cut through the knights moves of ,
,
. Also, if White gets sealed in on the top, Black can start a ko with a move at a (continuation is double hane). This can be a risky ko for Black because if White wins, the moyo on the right can get drastically reduced.
To prevent the ko possibility, sometimes White plays a before or plays one point below a very soon after this sequence.