3-4 point distant low approach, one-space low pincer
Suppose plays a pincer. White has prepared for that - is played to have a good option towards the corner in this case. Nevertheless, if Black wants to build influence towards the upper side, is a very good option.
There are a few cases (3-4 point distant low approach, one-space low pincer, tenuki) of White playing tenuki after .
The order of and in the previous diagram is important. If Black plays the atari at here first, White has the option of answering with the counteratari at and capture . Usually this is better for White than the joseki. If Black chooses the correct line of play, White has no alternative.
xela writing in early 2024: This is another urban myth that AI has dispelled. Even before AI, there's a small number of pro games on record with this "wrong" move order. And what happens? White just plays at and it transposes into the usual joseki. The order doesn't matter. Asking KataGo (with star points in the other corners), in this diagram and at as per the usual joseki are equally good and should give the same result with best play. The shown here is a small mistake. The difference is small enough that you could maybe call this an alternative joseki, but you can't really call it a mistake by black.
The standard variation continues with here. Up to , White gets a solid group and Black builds thickness. can be played at a instead, but that does leave bad aji and is now infrequent in pro games.
SnotNose Here is another possibility, though I'm not sure what the proper continuation is.
The purpose of is to induce , making natural. It looks like white has bad aji here unless he plays at or around a next. Perhaps I haven't got quite right (???).
Charles From the point of view of basic suji, is the previous diagram is worse than here, in reply to .
SnotNose It still seems that white has bad aji at a and, so, may need a protective move at or around b or c at some point.
Charles This is the most usual finish to the joseki.
One should consider that (of the Yup diagram) will probably be played, anyway.
Having written that, I then found that the first diagram line is known in pro games - even recently - when White wants to push on up into the centre. So, it could be joseki, too: but less common.
Playing instead of looks logical, but in the sequence to , White collapses. After , killing the corner with a and attacking in the center with b are miai for Black.
If White is willing to give something up in the corner, so as notto be enclosed, she can play at . Black can exchange Black a for White b in sente, but usually he will not do so, because the marked stone still has a lot of aji (Black b creates a ko, for example). More usually, Black either plays tenuki or pushes up with .
Alternatively, White can play at instead of . Pressing against the black stone in the corner, she strengthens it, but also strengthens her own stones. After , the joseki continues with White a or b. Compared to the previous joseki, we get a reversal, with White facing the top and Black the left side.
Black can also play here. Black now takes the corner, giving White the outside.
White can also cut, with at : this leads to a transposition to the joseki above.