3-4 point low approach three-space low pincer
This pincer has a very distinguished history, from Dosaku onwards, and is still very much in use today.
wild guess - strong player please fix this: This pincer is typically used as a pseudo wedge? when black wants to prevent white from establishing a moyo on the top. is useful because a more narrow pincer at a or b would be easier for white to counter pincer on the right, however,
exerts less pressure on
.
in the low position (vs
at c) is used to make it less easy for white to seek immediate life by sliding under with
, and easier for black to make a viable group on the top, but doesn't have the influence that a high pincer at c would.
Other replies frequently seen are d to h, and i as part of an overall plan. White e tries to avoid the counter-atari line after White f, but can lead to complex variations when Black answers at f.
e is discussed in some detail in the first chapter of The World of Chinese Go by Guo Juan.
White's slide to s was fashionable for a while in the 1980s.
Pincer josekis are complex; the following diagrams only shows the most basic variations.
[01]
In this case, moves like 'a' or 'b' can be considered. Notice for moves like this, white is inducing black to make territories on the left, therefore the normal idea is to pressure the pincer stone with 'c' after while making a moyo on the right.
When black has the upper right, white is not sure if white can get profit from attacking, so setteling with 'a' is common. 'b' is the same aim, but it's not recommanded.
If black plays 4 at 5, then it goes back to the previous diagram. However, black can atari from underneath, and this is probably not what white wants in this case.
White has different forcing move and/or end game move depends on how black address the lone white stone.