So this week I'd like to discuss a commonly visited joseki that many have probably seen before which is this one below:
So originally, I was going to make this post about which joseki to play in this situation, but after running my results with KataGo AI, it seems I was wrong myself in the general choice of joseki.
So I was going to give reasons for why black should always cut at B in the diagram above, but actually, in most instances, it seems, at least to KataGo, that black will play at A. So let us examine some of the joseki variations of B first:
So the first 2 joseki are old joseki that I grew up learning with the attachment at 8 and black's extension at 9. Both groups seem to settle quite comfortably leaving aji in both situations. However, the more modern joseki in the third diagram is much more common nowadays and more of a complex battle, that doesn't allow black to settle completely comfortably. My guess, is that B is actually overplay, and white's move at 8 in the third diagram serves to punish black.
So if B is indeed overplay, then the preferred joseki of choice is actually surprisingly to be at point A.(I'm not completely sure because I don't know if KataGo searched deeply enough). The variations leading off of this joseki involve white creating a wall while allowing black to settle for territory as show below:
I always thought that because of the promising enclosing move by white, and the ineffectiveness of the black stone at the triangle point, that this joseki seemed to be too good for white. However, I can see the that the triangular stone is actually very light and black seems to be very happy with just securing territory on the side and in the corner. So upon re-examination, it feels that this joseki is actually quite good for black.
I don't think that it's necessary to go into detail about how black can escape the triangle stone, so that'll be all for this week's joseki section. I hope this was helpful!