BQM 15

  Difficulty: Advanced   Keywords: Opening, Joseki, Question

This comes from my game in the second round of the Moscow tournament, against a 1 kyu, who has already 2200 points EGF rating, so he's really 2 dan.

Early in the game, I made a mistake in joseki. In the end, the result favoured ... me. I will discuss the several mistakes made, and I invite you to comment on them. If possible, can you give an estimate of how bad each mistake is in points ?

[Diagram]
From a tournament game  

White adopts a sansan strategy. I was surprised by W4, since I didn't know it.

[Diagram]
From a tournament game  

At black+circle would now be joseki[1]. I thought it was submissive.

[Diagram]
From a tournament game  

Fighting spirit urged me to block at B1.



This was a mistake and my opponent knew how to punish it. Pulling back to a and allowing him to cross underneath was out of the question, if only for reasons of shape. A Russian 5 dan told me it was probably best to abandon the bad move at B1 and simply block at b. White gets the advantage, but the game is still playable (for an amateur).

[Diagram]
From a tournament game  

So again, fighting spirit made me play B1. Of course White cut at W2 and I cut at B3.


BillSpight: The Suzuki-Kitani "Small Joseki Dictionary" (Joseki Shojiten) gives the following variation:

[Diagram]
Variation 1  

I confess I would not have found B1 in a real game. Does anybody know how Black should continue if W2 is at W4? Perhaps the following?



Dnerra: I confess if I had seen just this diagram, I would have expected it to be the starting point of a "What went wrong?"-thread, not to be a sequence quoted from a joseki dictionary. Doesn't White have more territory? OK, maybe Black's shape is a little better towards the center, as he can jump to a, but White cannot jump to b. I still like White a lot better here.

Bill: Oh, the dictionary says that White is better, too.

[Diagram]
Variation 2  
[Diagram]
Variation 1: the ladder  

See double threat ladder-maker.

DieterVerhofstadt:

Variation 1 works if the ladder at a is favorable. If not, then White can extend at B7. So if the ladder is unfavorable, you have to cut. Kogo's Joseki Dictionary


[Diagram]
From a tournament game  

A peaceful continuation now lies in Black playing at a. Again White would be better off, but the game remains playable.
Not with this tenacious guy. I played B1. If White now answers at b, matters get only worse: I lose either the top stones on a large scale or the three stones on the left. Fortunately now my opponent chose to settle for peace, which is in my favour.

[Diagram]
From a tournament game  

A 4 dan commented that W8 would have been better at a.

[Diagram]
From a tournament game  

W4 at B1. White has 10+ points. Black has a thick wall facing the center. White can cut at a, but that would only please Black, since he'll sacrifice two stones for more thickness towards the right. This result favours Black, but the difference is not so big, I think. Anyway, not something to repeat.

--DieterVerhofstadt


BillSpight: The fact that White does not now want to cut at a shows the futility of W6 - W8 in the previous diagram. If White pushes through with W6, she should play atari at a right away.

Also, W2 - W4 in this diagram is premature (if correct). Yes, it is sente, but not urgent, and there are larger plays about (such as a wedge on the right side).

[Diagram]
Sente?  

I'm not sure if W1 is sente or not, but if it is, isn't this better than capturing black+circle? And if it is gote, then it is clearly better than doing so (by definition).

dnerra: Eeek! Bill, I have to confess I strongly disagree. Letting Black capture the four white stones looks like almost like a losing move even at my level to me. Giving Black thickness without a single flaw would seem unbearable to me if I were white. Interesting disagreement, I would be interested about the opinion of a stronger player. (I agree with your comment above that White should make the atari at a after pushing throught, however.)

Bill: Which is better? Err, I mean, which is worse? ;-)

[Diagram]
Save the stones  

Captives: black+square black+square black+square

[Diagram]
Sacrifice the stones  

Captives: black+square black+square white+square white+square white+square white+square

Steve Kroon: Also note that in the first diagram Black has the next move, while in the second diagram, White has the next move.

Bill: White has the move in both diagrams. In the first, Black has played black+circle.

Steve Kroon: Absolutely correct, sorry. Excuse my ignorance, but why would Black spend a move there now? Surely a move on the right side is more urgent? i.e. shouldn't the first figure have black+circle somewhere along the right side, and the position then evaluated taking into account that white could start a fight with a cut at the current black+circle?

unkx80: The black+circle move is a thick move. Assuming the surrounding areas are neutral, allowing White to cut splits Black into two groups... definitely I won't call this Black group a thick group anymore.

Bill: Especially with the stone on the top right star point the connection is at least as big as an enclosure.


[1]

[Diagram]
joseki - TippyTable  

White gets to pick a or b.


BQM 15 last edited by 139.55.41.201 on August 25, 2005 - 06:37
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