4-4 point low approach two-space low pincer
This is a special-purpose pincer, as used in contemporary play.
Why is this a special purpose play? I played this the other day in the club in a 4-stone game and my opponent looked like I'd given him a present, but nothing too bad seemed to happen. Did he just mess up, or is there no way for white to really punish this move?
Dave: I think that Charles means to say this pincer is not ordinarily found in modern professional play. It only shows up in relation to other stones in the upper right.
As to why it is not common, consider what happens after White jumps into the corner and the usual follow-ups are played. If now Black played at a, the pincer would feel overconcentrated. On the other hand if White jumps out to , the pincer feels slack.
Bill: Suzuki and Kitani's Small Joseki Dictionary also state that the two space low pincer is rare. (And that's historically.) However, they give the above as joseki, with the comment that you can't say that this is better than having a three space low pincer.
The fact that it is still rare does not mean that expert opinion about it has been revised.
They also say that
in response to the double kakari produces a somewhat favorable (omoshiroi) result for Black.
This was at a time when the usual advice was to attach to the stronger stone, suggesting a play at a instead. Today pro opinion about that advice has changed.
White's ordinary answers are at a, b and c. The jump out at j, standard in old Chinese games, is sometimes seen.