Migeru's Question 2

  Difficulty: Advanced   Keywords: Joseki

This is a strange joseki from a game with jsha on NNGS. I would like some comments from someone who knows what they're doing.


I was very surprised by B4.


I wonder whether I should have played W9 at a.

As it turned out, Black ended up losing the corner.

Bill: How about W9 at b? Play around with it.


Migeru - Let's see...


B1 captures in a capturing race.

W2 threatens to play at B3.

B3; W4 - not at a!

Bill: W2 should descend.


Now what for Black?

Jasonred : I thought the same thing! (that's what I would do here). But then I read his line about the capturing race, so I thought, oh, that's not so good, I must have misread it.

Bill, could you read out the sequence for us?

Bill: Hint: White threatens a and b.

Whole board position - Immediate cut.  

Black's marked stone in the top right breaks the ladder, so White does lose the capturing race. However, White can still get a local advantage. First, she adds a third stone (White 5) as a sacrifice.

Charles How about W7 at W9 here? Black is unlikely to answer at a, early in the game.

Bill: Oh, I don't know about that, Charles. Which do you prefer as Black?

Option 1  

B5 fills at white+circle. (This squeeze is better for White than the suggested sequence.)
(Note: I am afraid that I have committed the same sin that yose books do. W6 - B9 is out of order. It is White's sente, so we assume that it gets played, but it is only worth 7+ points, and will wait. White should play at 10 first.)

Option 2  

B1 secures the corner and halfway saves the marked stone, but is not as strong towards the left side.

Charles Well, if White wants to treat Black at w as gote now, perhaps play W4 at p and invite Black to treat the lower side as a fighting area (rather than open-skirted). That way White's moves like r or s might come into the game. I don't suppose it's a case of absolute judgement here.

Bill: Well, considering Black's strength on the left side, I think that the cut is premature, anyway. :-)
I had rejected the - what do we call it? Semi-net? -- because of option 2. But on reflection, I think that both options are better for White than the one I suggested. Thanks, Charles. :-)

Immediate cut (ii)  

White's corner stones, having eye-shape, do not require an extension, but W1 is a good play.
Later, W3 - B6 is sente. (So we assume it gets played.) Still later, Black has a throw-in ko with Black a - White b, Black c, but the black corner is overconcentrated and the marked Black stone is mochikomi. Still, the immediate cut is somewhat doubtful, as aji keshi.


I think White should extend along the lower side after B8. In effect, Black will have exchanged the black+circle stones for the white+circle ones. White's gain in thickness is worth much more than Black's attempt at enclosing the corner, especially because of the cut at a. Any black attempt to save the stone will only be welcomed by White, since it means that Black is taking gote again for just a few points. Furthermore, the sequence B1 to B5 also gives Black a shortage of liberties, making the cut at a even more dangerous - Andre Engels


I think it's probably a mistake to try to cut B4 off at all. How about Wh5 here? If Black now plays at a, White slides up the left side to b. (If Black blocks at c, of course White plays a and 4 is captured.) This depends upon how important the lower side is to Black, but W1 has aji in any case. Andrew Grant


This line might be useful for White on occasion. But isn't it rather a thin way to play, in general? Black has in reserve the threat of Black a, White b, Black c. That has consequences, for example for Black closing off the side at e: it looks like White will want to play at d, and white+square will be weakened.


To contrast with that, isn't White relatively thick here, simply adding white+circle as extension? Of course it depends a bit on the overall position. But I don't see this as a real victory for Black. Charles Matthews

DaveSigaty: What was the overall position?

  • Was there a relationship in the upper left that led Black to play the initial two-space jump?
  • Was there a relationship in the lower right that caused White to choose the slide? (Why for example, did White not leave this area as it is in hopes of invading Black's position later?)

Migeru: Gee, Dave, do you want to embarrass me (and possibly jsha) with my (our) fuseki of 8 weeks ago? My guess is that I was just going through the motions: approach-slide-extend.

- Migeru 12k-Jsha 14k - B+31 - NNGS December 7 -  

White 11 at a, Black 12 tenuki.

Dave: No need to worry about embarrassing yourself. If we are not embarrassed about something in each game we play, we just haven't bothered to look at it honestly yet (at least this is 100% true for my games :-)

I was kidding, of course
I wasn't, unfortunately :-)

With the upper side wall, B2 is a nice attempt to squeeze a little extra out of the position compared to a "normal" one-space jump for example. At the same time it is inevitably thin. White should not be eager to cause Black to strengthen this position. Therefore instead of the slide at W3, White might have simply played b. This indirectly exposes the thinness of B2. Against the W1-b position Black normally looks forward to invading at c. If he does so here, however, his thin position on the left will be threatened more by any thickness White builds in the center. He may come to wish that he had played the stronger one-point jump instead.

Three Slides

A reasonable exchange for White  

Black ends up overconcentrated. In current professional play, Black will often play tenuki instead of answering at B2.

An open question  

There is debate in modern practice over whether White should exchange W1 for B2 although this was considered completely natural in the past. See changing fuseki dogmas

Black is happy  

This undoubtedly fixes up the thinness of Black's initial play.

Where next?  

Looked at differently, if black+circle and white+circle were already on the board, where would Black prefer to play next: a, b, or c?

Since Black should be happy to answer the slide with a play at 3-3, was the cut at B4 in the original diagram an overplay? What was the result?

  • Black got slightly more territory in the corner.
  • Black created and then had to protect (at least partially) a cutting point in his own position.
  • White became extremely thick along the lower side.
  • White was able to finish with a more aggressive knight's move toward the center rather than the usual two-space extension.

It seems to me that White can be satisfied with this result. Since there are still defects in Black's left side, I would be interested to know whether you were able to invade the left later in the game.

Let's see - Migeru

moves 106-115  
moves 116-125  

Black 126 at a, White 127 at b

moves 157-160  
moves 179-188  

I was just playing kikashi to try and live... and I got a snapback out of it.

moves 189-198  

White 11: I was too busy setting up a snapback in the upper left to see that I needed to protect against Black 12 at black+circle.

Moved from Migeru.

Migeru's Question 2 last edited by tapir on December 21, 2010 - 00:24
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