3-4 point, 5-4 approach, one-space low pincer, attachment

    Keywords: Joseki

Table of contents


1. Attachment + cut

[Diagram]

Joseki

Black cuts at B2 and W3 is forced. Next there are the old continuation at a and a rather new one at b.

For B2 at b see lower down.

For B2 at B3 see 3-4 point high approach one-space low pincer attachment noseki.


1.1. Crawl

[Diagram]

Extends

When Black crawls, W2 wedge is tesuji. See [1] for the plain atari at a.


1.1.1. Atari from above

[Diagram]

Joseki 1

[101] This is one standard sequence. At W7, White can choose this peaceful variation: she can also turn at B10, depending on a ladder. Black gets corner territory and influence on the left side. White gets influence on the upper side and sente.


1.1.1.1 Mistake in move order

[Diagram]

wrong move order

This is the wrong order of moves. Now, W9 is not sente since a is not necessary for Black to preserve the position.

So, White loses the initiative here. As a minor plus, she has b in sente later.

[Diagram]

Wrong order punishment

Black can use his sente locally to get much more of the corner. 10 is technically gote, but white's shape is rather pathetic after a cut at 'a', or just simply capturing the stones at 'b'.

[Diagram]

Right order, wrong answer

This is a better result for White. White has sente and much more of the corner. The atari at 'a', for Black, is no longer as good a move.

[Diagram]

Wrong order, trick play

9 is a trick play. 10 is one answer. 'a' is also possible.

[Diagram]

Wrong order, trick play, continuation

This is one possible continuation. White's play is inconsistent and presumably bad -- the lone white stone on the outside was presumably played to obtain influence. If White moves out with the two stones, for example 'b', instead of allowing 5 and 7 then Black can save the inside stones in a variety of ways, for example, 6 or 'a'. A fight then proceeds on the top side, one possible variation involves a ko fight.

[Diagram]

Wrong order, trick play, fight

Note that the 'a'-'b' exchange is bad for white. White can never play 'e' because Black has 'd' to shorten the liberties on the two white stones (i.e., if 'c', then 'd'). A ko-fight results up to 8. If White loses this ko, White loses everything in this quadrant of the board. If White wins the ko, Black still has a perfectly fine wall on the left side and loses only a few points compared to the main variation. One presumes Black will win the ko ;).

[Diagram]

Ko unavoidable

White cannot back down from the ko; if 1, then the tesuji at 2 kills White via double-ko. I.e., Black will either have the extra liberty at 'a', or will have a black stone at 5, threatening capture.

[Diagram]

Ko unavoidable (2)

White cannot achieve a good result this way either; White dies in the corner and is left with a serious cutting point (i.e., gote). Playing 'a' first leads to the same followup sequence, only Black can delay answering 7 at 8 until White plays 9 or 1. White at 6 should be answered by Black at 8.

Black, however, can avoid the ko fight.

[Diagram]

Black avoids ko

The result is better for Black than in the joseki, but not nearly as good as Black winning the ko. Note that white still lacks eyes, unlike the joseki. A move at 'a' would fix that immediately, but Black can aim at forcing White to actually play such a worthless move.

[Diagram]

Wrong order, trick play, atari

Black can also choose this way, if influence is more important, and the ko fight is hard to win. The circle-square exchange isn't terribly urgent, as it is essentially Black's sente. This result is similar to the first variation given for answering White's trick move; white has a bigger corner, but the open-skirt is now on the top side instead of the left side. This is probably good for black -- to have arrived at this variation in the joseki, before the trick, white ought to have influence on the top, and black on the left.


1.1.1.2. Trick play diagonal

[Diagram]

Kosumi

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

[Diagram]

Kosumi continuation

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


[Diagram]

Variation: the ladder question

At W7 in the previous diagram, White can turn at W1 here. Everything depends on the ladder at B6.

[Diagram]

Variation: ladder question

If the ladder doesn't work for Black, instead of playing a he must extend at B1. After W4, there is a peaceful play for Black at b and a fight at a.


1.1.1.3. Alternative joseki

[Diagram]

Black leaves the main line

Playing B4 instead of 'a' is an idea proposed by Lim Yoo Jong. It leaves White no scope for variation (in the main line White can play W5 at B6 depending on a ladder), and White has fewer ko threats. On the other hand Black's eyes are a little less well defined. Click here for more analysis/discussion.


1.1.2 Atari from below

[Diagram]

Ladder question

Here, it depends on whether White can cut at a and capture the black stone in a ladder. See pushing battles in joseki 8 for a fuller treatment.

[Diagram]

Almost joseki: The ladder works for White

If the ladder works, Black submits with B1 and B3, getting a low position but keeping sente.

Black cannot ignore W2 to play 4; White cuts at 'a' and gets a ponnuki on the outside, or captures the 4 black stones in the corner. More importantly, and for the same reason, Black cannot answer 2 at 'b'.

If the moves W2 and W4 are played in the wrong order, Black can double-hane, at 'b'.

[Diagram]

Black punishes wrong-order

The cutting point at 'a' goes nowhere after the 2-3 exchange. It is usually impossible to severely attack 5 after the cut at 'b'. Indeed, the white cutting stones ought to come under heavy attack, considering black chose a pincer on the left side (so it shouldn't be dominated by white influence).

Guo Juan commented that an additional push is joseki.

[Diagram]

Joseki?

Variations if Black ignores W4 (to play 6) are not analyzed here. Presumably W8 should in fact be one line further away, since the wall is one line higher. One also hopes that it makes sense to play W8 (W6 in the prior variations) on the 4th line, since a wall this high is somewhat silly if there is black influence further down the right side (a reason to play W8 low).

[Diagram]

The ladder doesn't work for White

If the ladder doesn't work for White, this is joseki.

[Diagram]

The ladder doesn't work for White

Black crawls on one side but gets ahead on the other.

[Diagram]

Variation at 3: two ponnuki

This variation occurs in the 11th Tianyuan title match, game four between Ma XiaoChun and Chang Hao. Locally, White's profit is considered better than Black's influence along the left side but Black takes sente.


1.2. Atari

[Diagram]

Joseki

Against B1 and B3, W4 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.

[Diagram]

Not joseki

W4 here is not so good. The marked stone is under little pressure and Black will find it easy to dispose of the situation.


2. Attachment + hane

[Diagram]

Black plays on both sides

This is a well-established line too. Next White plays a (simple), or b, c which are both complex.

Recently there have been experiments with B4, also.

[Diagram]

Weakness at a.

If black plays at B4 here, it leaves a weakness at a which can be exploited after white plays the marked stone. (A play at x by black would be even worse, allowing white to play at a immediately.)

[Diagram]

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'.


[1] Atari instead of tesuji

[Diagram]

Atari

If White exchanges W1 for B2 before playing W3, then Black can play B6 and gain considerably compared to the joseki. [100]

[Diagram]

inferior for white

Black simply extends down the left in response to W2.

[Diagram]

white gets bad shape

white+circle becomes overconcentrated when white captures B4. If W1 at a instead, black extends across the top to the right to b



This is a copy of the living page "3-4 point, 5-4 approach, one-space low pincer, attachment" at Sensei's Library.
(OC) 2008 the Authors, published under the OpenContent License V1.0.
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