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[go]$$Bc The move under discussion
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$$ | . . . O . . . . . , . . . . . X . . . |
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$$ | . . . . . . . . . . . . . . . . b . . |
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$$ | . . . . . . . . . . . . . . . . 2 . . |
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$$ | . . . . . . . . . . . . . . . . 1 . . |
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$$ | . . . X . . . . . , . . . . . O . . . |
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I have seen this move in the context of old Chinese games, to prevent moyos, and Sensei's library has a very short discussion on it. Has anyone tried playing this enough to get a good feel for it, and what were your conclusions?

As black, I've done okay diving into the corner, though I think my opponent misplayed. In that game, black had also played 3-3 in the bottom left, not 4-4. Double approach seems reasonable as well. The A-B exchange seemed too easy on white, though since black will probably take sente out of the situation, and plays first in a symmetric position, you would expect black to have the advantage. I didn't like the idea of letting white settle so easily though. Any thoughts?

I like the double kakari here, the downside to a "pincer" that long is usually that it doesn't put much pressure on anything. If it is approached, it becomes useful, so my take would be, don't approach it, let white get 2 2-space extensions if he wants them.

_________________
Tactics yes, Tact no...

I like the double kakari, too. The right side per se is not very interesting right now.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

I faced this a number of times in teaching games with pros. There is nothing special about it (maybe that is what makes it special?). Rather it was used then to demonstrate the ideas of miai and balance. No matter what you think you ought to do against it, you can't really. By the same token, it is not a severe move so the next choice really is up to you. It will play a role in whatever unfolds next. Will you do a better job of taking its potential into account or will your opponent? That's the essence of Go, right?

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Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21

Are there other moves you think of especially as 'teaching moves' like this one, then?

I would reason like this (and perhaps it's why I am not a strong player):

If white extends towards , that will be a really nasty pincer. So I will extend to a. White's will make a base by extending to b, but that's no problem because the whole top side is still open so my hoshi stone is in no great danger. Later, playing at O3 or somewhere nearby looks good because of my half-settled group on the right side.

What is wrong with that thinking?

_________________
Poka King of the south east.

If White extends towards , making a one space pincer, Black can jump into the corner at the 3-3 and the result will be the same as joseki, but with an extra White stone on the right side, which means that White will be a bit over-concentrated. (Over-concentration is a relatively modern concept.)

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

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[go]$$B Var A
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$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . , . . . . . X . . . |
$$ | . . B O O 1 . W . . 2 . . . . . . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]

Hi Bill, is it a consensus among pros that ends up a bit over-concentrated (a recent one ?) ?
I was under the impression of the opposite.

It's not nasty at all. ( What's so nasty about it ? ) It's perfectly reasonable,
and as Bill mentioned, B can simply jump into 3-3 (see Var A above). Very peaceful result, locally.
( Of course, depending on the whole board, B may not want to jump in to 3-3. )

It is an inference I draw from this diagram.

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[go]$$B Joseki?
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$$ | . . 9 . . . . . . . . . . . . . . . . |
$$ | . . . 4 . . . . . . . . . . . . . . . |
$$ | . . 3 O . . . . . , . . . . . X . . . |
$$ | . . 1 2 8 B . W . . 0 . . . . . . . . |
$$ | . . 7 5 6 . . . . . . . . . . . . . . |
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$$ -----------------------------------------[/go]

may occur at this point in some pro games, but I do not believe that it is considered to be joseki. So it is a bit over-concentrated.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Lee Changho likes that 2 space extension after the one space pincer take the corner joseki, though obviously it depends on the situation.