Twitchy's Corner

Create a study plan, track your progress and hold yourself accountable.
Twitchy Go
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Re: Twitchy's Corner

Post by Twitchy Go »

@edlee
Fair enough assertion.

A follow up question. If you had two groups that were undoubtedly alive and your opponent cuts inbetween them. Would that still be broken shape?
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Post by EdLee »

Twitchy Go wrote:If you had two groups that were undoubtedly alive and your opponent cuts inbetween them. Would that still be broken shape?
Broken shape is not about the life-and-death status of the groups involved. :)
Also, a cut is not the same thing as a broken shape. :)

Ancient Go proverb: don't cut two live groups. So if your opponent cuts between two live groups,
his reason can not be to attack either one; it must be for other purposes.
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Re: Twitchy's Corner

Post by jts »

Twitchy Go wrote:@edlee
Fair enough assertion.

A follow up question. If you had two groups that were undoubtedly alive and your opponent cuts inbetween them. Would that still be broken shape?
You would still call it broken shape. Whether it's bad or not is another question. Certainly knowing that both of the separated groups are 100% alive removes a major concern, but there are others.

1. Are you really, truly 100% sure they're alive? :-)
2. What about all the stones that are hanging off your two live groups - are they all completely connected after your shape is broken?
3. What about the enemy's groups - were they both completely alive? If he broke your shape he may have connected two groups that would have been cut otherwise, and might have been separately weak or dead.
4. When he breaks your shape, is he playing moves on dame or breaking into your territory? When you get enemy stones reducing your territory you can block, and when you have stones running around inside your territory you can kill, but when he breaks your shape, abandon all hope.
5. Did he create aji or cutting points in sente?
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Post by EdLee »

Twitchy Go wrote:If you had two groups that were undoubtedly alive and your opponent cuts inbetween them. Would that still be broken shape?
Follow-up:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . . . . . . . . . .
$$ . . . . O O O . . . . . . . .
$$ . . . . O . O . . . X X X . .
$$ . . . . . O . O . . X . X . .
$$ . . . . . O O O . X . X . . .
$$ . . . . . . . 3 2 X X X . . .
$$ . . . . X X X X 1 . . . . . .
$$ . . . . X . X . O O O . . . .
$$ . . . X . X . . O . O . . . .
$$ . . . X X X . . . O . O . . .
$$ . . . . . . . . . O O O . . .
$$ . . . . . . . . . . . . . . .[/go]
Above: there is no broken shape, and :w1:, :b2:, :w3: are all passes.
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . . . . . . . . . .
$$ . . a . . a . . . . . a . . .
$$ . . . . . . . . b . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X . . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . . . O . . . . . .[/go]
For the second case, it depends on whether the (a) areas are important to Black.
If yes, then B should block at (b); otherwise W pushes through at (b) -- broken shape.
If no, and W still pushes through at (b) -- yes, it is locally a broken shape -- but if the result is not bad for B, then it's OK.
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Re: Twitchy's Corner

Post by Twitchy Go »

Thank you both for the qualifiers. It is helping me to understand the broken shape concept. What had been confusing me was that it seemed as though if your fine with your opponent pushing through you can get at least a few free moves out of it which can be worth a good bit. It is bad then to create broken shape without realizing that will be the result, and while not great, it can be acceptable to consiously allow the shape to be broken if its not horrible locally and you can get something out of it.

Ignoring all of W extra moves :)
If W wants to push through. Both his groups are strong. And with two huge walls so close to each other. Neither side can make any territory out of a. Thereforing playing somewhere else instead of b would be good here?
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . O . . . . O . . .
$$ . . . . . O . O . . O . O . .
$$ . . . . O O O O O O O O O O .
$$ . . . . . . . . . . . . . . .
$$ . . a . . a . . . . . a . . .
$$ . . . . . . . . b . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X X . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . . .
$$ . . . . . . O . O . O . . . .[/go]
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Re: Twitchy's Corner

Post by Boidhre »

Just a point to see if my thinking is wrong: To me white's 1 there looks fairly pointless. Why cut two live groups? White's group on top is alive so it doesn't need to be connected etc.
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Re: Twitchy's Corner

Post by Twitchy Go »

Boidhre wrote:Just a point to see if my thinking is wrong: To me white's 1 there looks fairly pointless. Why cut two live groups? White's group on top is alive so it doesn't need to be connected etc.
You are correct, at least as I understand it. The discussion is on broken shape, and I think I created(well edited) a diagram where broken shape is inconsequential. That was the idea at least.
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Post by EdLee »

Twitchy Go wrote:Thereforing playing somewhere else instead of b would be good here?
Yes. :)
Twitchy Go wrote:to understand the broken shape concept.
Continue to play, study, and review. :)
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Post by EdLee »

Boidhre,
Twitchy Go wrote:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . O . . . . O . . .
$$ . . . . . O x O . . O y O . .
$$ . . . . O O O O O O O O O O .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X . . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . .
$$ . . . . . . O . O . O . . . .[/go]
Boidhre wrote:White's group on top is alive...
Very close, but not 100% -- x and y are not real eyes yet. :) Baby edit:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . O O . . . . O O . .
$$ . . . . . O . O . . O . O . .
$$ . . . . . O O O O O O O O . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X . . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . .
$$ . . . . . . O . O . O . . . .
$$ . . . . . . . O O O . . . . .[/go]
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Re:

Post by Boidhre »

EdLee wrote:Boidhre,
Twitchy Go wrote:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . O . . . . O . . .
$$ . . . . . O x O . . O y O . .
$$ . . . . O O O O O O O O O O .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X . . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . .
$$ . . . . . . O . O . O . . . .[/go]
Boidhre wrote:White's group on top is alive...
Very close, but not 100% -- x and y are not real eyes yet. :) Baby edit:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . O O . . . . O O . .
$$ . . . . . O . O . . O . O . .
$$ . . . . . O O O O O O O O . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X . . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . .
$$ . . . . . . O . O . O . . . .
$$ . . . . . . . O O O . . . . .[/go]
True. I'm blind. :)
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Re: Twitchy's Corner

Post by jts »

Just one note on some ambiguities in the concept of broken shape.

1. The shape that results from ignoring a peep at a basic jump.
2. The shape that cuts one player's groups of stones cleanly apart without similarly cutting his opponent's.

In the case of the keima these two conceptions lead to the same conclusion, but in the case of the one-space jump they lead to two slightly different conceptions of when the shape is broken. The first conception suggests that this is a broken shape:
Click Here To Show Diagram Code
[go]$$W The marked stone is the peep B ignored.
$$ . . . . . . O . . . . O . . .
$$ . . . . . O . O . . O . O . .
$$ . . . . O O O O O O O O O O .
$$ . . . . . . . . . . . . . . .
$$ . . a . . a . . . . . a . . .
$$ . . . . . . . . 2 . . . . . .
$$ . . . . X X X X 1 X X X X . .
$$ . . . . X . X . W . X . X . .
$$ . . . X . X X . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . . .
$$ . . . . . . O . O . O . . . .[/go]
The second conception suggests this is the broken shape:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . O . . . . O . . .
$$ . . . . . O . O . . O . O . .
$$ . . . . O O O O O O O O O O .
$$ . . . . . . . . . . . . . . .
$$ . . a . . a . . . . . a . . .
$$ . . . . . . . . 1 . . . . . .
$$ . . . . X X X X W X X X X . .
$$ . . . . X . X . O . X . X . .
$$ . . . X . X X . O . . X . X .
$$ . . . X X X . . O . . X X X .
$$ . . . . . . . . O . . . . . .
$$ . . . . . . O O O O O . . . . .
$$ . . . . . . O . O . O . . . .[/go]
A further point, however, is that whether a shape counts as broken depends on the local situation and what sort of connection B had between his stones. This might be obvious with the bamboo joint: compared to the one point jump, "peeping" the bamboo joint and then "pushing through" is useless and does not break the shape, although locally it looks the same as peeping and pushing through the one point jump. I bring this up because the huge number of stones surrounding W's peep in this example will affect our judgment of whether the shape is broken. An example more true to the spirit of the question might involve two strong groups connected over a distance by a series of 1-pt jumps.
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Re: Twitchy's Corner

Post by Twitchy Go »

Interesting, jts. That's some stuff for me to think about.
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Re: Twitchy's Corner

Post by SoDesuNe »

On a related note:
Click Here To Show Diagram Code
[go]$$Wc Dosaku (W) vs. Chitetsu (B)
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X X O O . |
$$ | . . O . O . . . . . . X . O O X O X . |
$$ | . . . , . . . . . , . . . X O X X . X |
$$ | . . X . . . . . . . . . . . O X . X . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . e . . . . . . . . . . O O . . . . |
$$ | . . X c . . . . . . . . . X O . O . . |
$$ | . . . a . . . . . . . . . . X X . X . |
$$ | . . . , . d . . . , . . . O X , . X . |
$$ | . 9 . . 8 5 b . . . . . . . X O O O . |
$$ | . 4 3 7 6 2 O . . . . O O . X O X O . |
$$ | . 0 X 1 . X . . O . O X . O X X X X . |
$$ | . . X O . . X . . O . . . . O . . . . |
$$ | . X O . . . . X X . X . O . O X X X . |
$$ | . X O O . O O O X , . X X X X O . O . |
$$ | . X X O X . O X O O X . . . X O . X O |
$$ | . X O O . . O X . . . . . O X O . O . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ ---------------------------------------[/go]
Now, is :w5: a bad play since after the sequence to :b8:, White has a broken Keima between :w5: and :w7:?
Furthermore: Black is forced to escape ("Squeezing Out the Toothpaste"?) while White is induced to defend a cut ("Thank-You"-move) and can both surround Black's lower left side group and attack Black's upper left side group with the sequence from 'a' to 'e' ("Make Territory while Attacking") while Black gets a Ponnuki in the center ("A Ponnuki is worth 30 points").

How to judge?

White won the game with 5 points. There was no Komi.
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EdLee
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Post by EdLee »

SoDesuNe wrote:How to judge?
Exactly. :)
Continue to play, study, and review. :)
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Re: Twitchy's Corner

Post by Twitchy Go »

Thanks you SoDesuNe
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