In reply to the pincer ,
is essentially always answered at
.
Now there are distinctive variations with White at a, or at b.
[1]
After ,
and
look like the key points for shape (
can also be played at c or d).
Now Black has to decide between pushing through at once at the square-marked point (the degiri of Kubomatsu) or strengthening the left side at one of the circled points.
Here for a table shape and
(see [...]) are typical good shape plays.
There is also a more rapid way to play: and then
to cross-cut. White can play next at the marked point. White would like to gather strength without making the
/
exchange above. This idea, however, may not be current in pro games.
The degiri
If Black goes ahead with Kubomatsu's play, up to is inevitable. Now
is blighted.
(This idea dropped out of pro practice, a generation ago.)
Assuming , something like this can be expected. Black's loss in the corner is large. In return he can attack White's floating group.
[2]
There is the calmer option of . The areas of a and b become miai.
If , the local joseki ends with
. Black may well have to defend on the upper side. [3]
Assuming to secure the cut, White will attack, probably at one of the marked points.
may presuppose a good ladder after
.
This has been played by Cho Chikun. Black may well now play tenuki, an idea that goes back to Shusaku. White's attack isn't very severe.
The Stratagem/Trap play
Can you see the trap?
How not fall into the stratagem/trap: Extend once more at a, when white responds with b, then jump to c.
Alex Weldon: How to answer if Black plays here? Happened to me in a game and I screwed up and got a very bad result. a seems natural, since it gives hane at the head of two (making the marked stone look like a bad move for Black, which it probably is), but what's the best way to handle matters if Black then cuts at b? Seems like the marked Black stone is kind of hamete, given what happened to me in the game.
then a