Joseki  

The attachment at is a common reply to the one space low pincer. Black will usually either cut at a or play hane at b. The immediate jump to c is a new pattern that is still being explored.

Table of contents Cut on the inside Crawl Atari Trick play diagonal Hane on the outside Two point jump Hane at the head - Noseki

Table of diagrams Joseki Cut Main line Atari Not joseki Kosumi Kosumi continuation Black plays on both sides Modern style Modern style - ctd Modern style - ctd (2) Modern style - var Black jumps White makes shape Taking the corner - Follow up 1 Extending on the side - Follow up 2 White ends with a "weak ponnuki" Typical mistake - White ends with only one eye in the corner, Black develops on both sides inferior for White White gets bad shape Wrong cut

Cut on the inside

Cut  

Black cuts at and is forced. Next there are the old continuation at a, which can be considered the main line, and a rather new one at b.

Crawl

Main line  

When Black crawls, wedge is tesuji. Without this move, the attachment in the corner would not be playable for White.

Next, Black can atari from above at a, or from below at b, these moves are further explored at 3-4 point, high approach, one-space low pincer, 3-3 attachment, cut and crawl

Atari

Atari  

Against and , is tesuji. An exchange takes place with Black taking corner territory and sente and White influence towards side and center. The result is considered slightly better for White locally but playable for Black in many circumstances.

Not joseki  

here is not so good. The marked stone is under little pressure and Black will find it easy to dispose of the situation.

Trick play diagonal

Kosumi  

An interesting move (but hamete) that has potential use in some situations

Kosumi continuation  

Black trades the corner and some stones to get development on both sides.

Update (mid 2024): KataGo thinks this is a terrible outcome for black! What's called "development" here is two groups that are potentially weak. Next, white should capture at a and feel happy. The diagonal move at was bad enough, but is the real mistake here. Instead, black at b starts a complicated fight with more potential.

Hane on the outside

Black plays on both sides  

This is a well-established line too. Next White plays a (simple), or b, c which are both complex. See 34 Point ,High Approach, One Space Low Pincer, 33-Attachment, Outside Hane, Large Scale Fight.

Recently there have been experiments with , also.

Modern style  

Kogo's joseki dictionary says that this is the modern way, and gives some variations which look rather complicated. Game search have found 121 pro games with this position, mostly played since 1997; a is by far the most common continuation (70/121), but all of b through e appear also. More SL analysis needed, a.o. about White forcing at 'f' then attacking at 'g'.

Modern style - ctd  

In http://www.gooften.net, Antti Tormanen continues to explain this joseki. needs a ladder. After , a would be a crude connection, leaving a peep at b that would force an empty triangle. Instead ...

Modern style - ctd (2)  

... itself forces an empty triangle and a connection through , while White fixes her shape. The whole board context then will decide on the timing of living with a, which will tend to be dominated by the fight for stability at the top. Incidentally, b is White's privilege and should be left unplayed to keep the option of connecting underneath at c, adter a has been played.

Modern style - var  

This variation, where Black connects underneath using , then extends to a, relates to ^[100] but is much better for White given the position of the stones. As Antti mentions in his article, White gets a thick position in sente while Black is low.

Two point jump

Black jumps  

is a fast play. White has some exciting and very tricky options. d and c are commonly played on Tygem. e: see BQM522.

White makes shape  

may be the most standard continuation. a and b both appeared as followups for White to strengthen her group, but it seems a variety of moves are being experimented with.

Extending on the side - Follow up 2  

tapir: MasterGo has a first isolated occurence in 1987 (Ha Chan Soek vs. Yang Su Yeong), and 8 games in 2007 and 20 in 2008 featuring this pattern (2009 games are not yet updated). Results are usually good for White (winning 63%).

inferior for White  

Black simply extends down the left in response to .

White gets bad shape  

becomes overconcentrated when White captures . If at a instead, Black extends across the top to the right to b

Wrong cut  

Cutting with - is no good. For analysis, see 3-4 point high approach one-space low pincer attachment noseki

See also: Pushing battles in joseki 8