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Odd seki [#2531]

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114.93.107.186: Odd seki (2011-03-21 12:40) [#8374]

GNU Go is stronger than I am in some ways, so I've been playing against it a lot, mostly at 9x9 for tactical practice. I think I've discovered a weakness; it is not good at avoiding seki; I sometimes get away with things I shouldn't. Here's an example, from a 2-stone game with me black. We were here as of move 24, W to play.

[Diagram]
 

White passed, which I suspect is a blunder. I think he should cover the vital point X, but I'm not entirely sure that is necessary. That's my question.

The next few moves were:

[Diagram]
 

Then

[Diagram]
 

We ended up with just a large black territory plus a large seki, complete disaster for White. But where did he go wrong? The pass? Or later?

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86.30.188.162: ((no subject)) (2011-03-21 15:25) [#8375]
[Diagram]
Grabbing the key points.  

IGS 5K+: I believe Black 1 is the most important point to play and that White should waste no time in occupying the other key point, White 2.

Up to 8 Black could play a, b, or c to start a ko but I see no chance of her winning any of them. If Black a, White b. If Black b or c, White a.

X
pashley: Re: Odd seki (2011-04-06 08:11) [#8393]

So you are saying White's pass in the original position is OK because he can defend adequately against Black 1 later?

129.67.184.43: Re: Odd seki (2011-04-21 19:18) [#8420]

IGS 5K+: In this partcular situation the game is complete to my eyes and White is behind on territory. I would pass (I prefer to pass rather than resign if the end-game has already been fought).

In general there is something to be gained from defending this group because otherwise if Black generates some ko-threats elsewhere she can use them to make a seki here.

84.250.84.15: Re: ((no subject)) (2011-04-19 05:07) [#8409]

Black would play B9 at b, and white would have to struggle to salvage even a seki.

129.67.184.43: Black's resistance (2011-04-21 19:16) [#8419]
[Diagram]
Black presses on.  

IGS 5k+: I don't see that White has any difficulties. If Black descends to B1 here then White can respond with W2. The sequence to W6 leaves Black with nothing.

[Diagram]
Another Try.  

IGS 5k+: Here Black tries cutting with B3 but this comes to nothing too.

[Diagram]
Leaving the ko for last.  

IGS 5k+: Because White has some ko-threats Black can't hope to win this ko.

Please show us if you have a stronger resistance for Black. I don't see anything better than these.

96.47.186.240: Re: Black's resistance (2011-04-21 23:37) [#8421]
[Diagram]
9@6  

Seki?

B@a looks to lead to an unfavorable ko for black (must find first threat).

86.30.188.162: Re: Black's resistance (2011-04-22 00:11) [#8422]

IGS 5K+: Ah! I didn't consider B7. It seems you are quite right and that Black can manage a seki after all.

Thanks for this.

 
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