4-5 point 4-3 approach keima, contact at 3-5, hanedashi
Black's move here has a long history (it dates back to the eighteenth century). It impresses amateurs, rather than pros.
The only variation that is worth mentioning is here, catching the black stone in a ladder. Obviously, white can only play this if the ladder works.
Continuing the main line, now White decides how to handle the cutting stone . Normally is played (the alternative is to play atari first at ). These are the standard plays, with White able to jump out as far as .
Now both sides try to arrange their shape on the outside, by playing moves against the inner groups.
There are a number of variations, but and are popular ( at the circled point equally so).
Since threatens Black on the left, to are required (White's choice of how to play clearly determines which side the peep is, too - if is played at instead, peeps at instead). On the upper side is honte but it is also possible to play directly at .
This is the joseki book continuation, assuming White wants to leave ladder aji on the outside, and that is a good ladder.
If white plays instead of a, black pushes in with . White answers with or . If , after white needs to play to live, and black fetches up his shape with .
In a pro game, naturally, the players adjust the way of playing the later stages of this joseki, according to the needs of the overall position.
Charles Matthews, additions by Andre Engels
LeelaZero prefers answering with , then only protect at After Black crawls once more, before making shape in the centre with and B0. After White a, it's time to play elsewhere, at least on a board which otherwise has only single stone corners.