Cutting point in 3-3 invasion joseki

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EdLee
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Post by EdLee »

While you work on :w8:, here's one follow-up question about the original :w20: in the Malkovich game.
W has two ways to fix that cut: tiger's mouth (right) or solid connect (left).
The tiger's mouth is better. Why? Try to name as many reasons as you can. (I have to crash now! :))
Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . X O . . . . . . . . . . . . . O X . |
$$ | . X O . . . . . . . . . . . . . O X . |
$$ | . . X O . . . . . , . . . . . O X . . |
$$ | . . X O 1 . . . . . . . . 1 . O X . . |
$$ | . . X X O . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
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PeterPeter
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Re: Cutting point in 3-3 invasion joseki

Post by PeterPeter »

I see it now, White forces a bigger capture after :w8: .
Click Here To Show Diagram Code
[go]$$B
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 4 0 O . . |
$$ | . . . . . . . . . . . . . 8 7 3 O X . |
$$ | . . . . . . . . . . . . . 9 2 1 O X . |
$$ | . . . , . . . . . , . . . . 5 O X . . |
$$ | . . . . . . . . . . . . . O 6 O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]

If Black captures with :b9: , White still gains after :w10:.
Regards,

Peter
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PeterPeter
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Re:

Post by PeterPeter »

EdLee wrote::w8: was bad -- try again. :)
PeterPeter wrote:White will capture with :w8: , and I slightly prefer White's position.
Click Here To Show Diagram Code
[go]$$B
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 4 . O . . |
$$ | . . . . . . . . . . . . . 9 7 3 O X . |
$$ | . . . . . . . . . . . . . a 2 1 O X . |
$$ | . . . , . . . . . , . . . 8 C O X . . |
$$ | . . . . . . . . . . . . . O 6 O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
This shape is a disaster for W. :)

Because Black can play at A?
Regards,

Peter
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EdLee
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Post by EdLee »

PeterPeter wrote:I see it now, White forces a bigger capture after :w8:.
Good! That's called a squeeze. :)
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EdLee
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Post by EdLee »

Click Here To Show Diagram Code
[go]$$B Shape disaster for W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . Q . Q . . |
$$ | . . . . . . . . . . . . . # # # Q X . |
$$ | . . . . . . . . . . . . . . Q # Q X . |
$$ | . . . , . . . . . , . . . Q . Q X . . |
$$ | . . . . . . . . . . . . . O O O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
PeterPeter wrote:Because Black can play at A?
(*) Because W's shape is crushed. See:
http://senseis.xmp.net/?SqueezingOutTheToothpaste
and
http://senseis.xmp.net/?SmallGaps
(*) Also, because W should've gotten the following result -- compare the two! :o
Click Here To Show Diagram Code
[go]$$Wm12
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O O O . . |
$$ | . . . . . . . . . . . . . O Y Y O X . |
$$ | . . . . . . . . . . . . 1 Y Y Y O X . |
$$ | . . . , . . . . . , . . . . Y O X . . |
$$ | . . . . . . . . . . . . . O O O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
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Uberdude
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Re: Cutting point in 3-3 invasion joseki

Post by Uberdude »

EdLee wrote:
Click Here To Show Diagram Code
[go]$$B Shape disaster for W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . Q . Q . . |
$$ | . . . . . . . . . . . . . # # # Q X . |
$$ | . . . . . . . . . . . . . . Q # Q X . |
$$ | . . . , . . . . . , . . . Q . Q X . . |
$$ | . . . . . . . . . . . . . O O O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
PeterPeter wrote:Because Black can play at A?
(*) Because W's shape is crushed. See:
http://senseis.xmp.net/?SqueezingOutTheToothpaste
and
http://senseis.xmp.net/?SmallGaps
(*) Also, because W should've gotten the following result -- compare the two! :o
Click Here To Show Diagram Code
[go]$$Wm12
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O O O . . |
$$ | . . . . . . . . . . . . . O Y Y O X . |
$$ | . . . . . . . . . . . . 1 Y Y Y O X . |
$$ | . . . , . . . . . , . . . . Y O X . . |
$$ | . . . . . . . . . . . . . O O O X . . |
$$ | . . . . . . . . . . . . . . O X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]


More importantly than any shape problems, white's 2 groups are now cut and separated, with no way to capture the black cutting stones. Maybe Ed forgot to say this because it's obvious, but I think it's important to emphasise to PeterPeter in case he missed it. Any bad shape considerations are secondary the the fundamental failure here that white should have captured the cutting stones to connect his groups, but has failed to do so and is now separated into 2 groups.
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Re:

Post by PeterPeter »

EdLee wrote:The tiger's mouth is better. Why? Try to name as many reasons as you can. (I have to crash now! :))

I must have worn out poor EdLee :), but for when he has recovered, I can think of 2 reasons:

1. It is nearer to, and therefore has more influence over, the shaded area.

2. Eyespace potential at A.

Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . X O . . . . . . . . . . . . . O X . |
$$ | . X O . . . . . . ? ? ? ? ? . . O X . |
$$ | . . X O . . . . . ? ? ? ? ? . O X . . |
$$ | . . X O 1 . . . . ? ? ? ? 1 a O X . . |
$$ | . . X X O . . . . ? ? ? ? ? O X X . . |
$$ | . . . . . . . . . ? ? ? ? ? . . . . . |
$$ -----------------------------------------[/go]
Regards,

Peter
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Uberdude
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Re: Cutting point in 3-3 invasion joseki

Post by Uberdude »

3. Think about yose (endgame).
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PeterPeter
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Re: Cutting point in 3-3 invasion joseki

Post by PeterPeter »

Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . X O . . . . . . . . . . . . . O X . |
$$ | . X O . . . . . . . . . . . . . O X . |
$$ | . . X O . . . . . , . . . . . O X . . |
$$ | . . X O 1 . . . . . . . . 1 b O X . . |
$$ | . . X X O . . . . . . . . a O X X . . |
$$ | . . . . . . . . . . . . . 3 2 4 . . . |
$$ -----------------------------------------[/go]


How about: after the standard endgame sequence :b2: :w3: :b4: , White does not need to worry about Black invading at A, but he would worry if :w1: were on B? And, therefore, White comes out with sente?
Regards,

Peter
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Uberdude
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Re: Cutting point in 3-3 invasion joseki

Post by Uberdude »

Yes, the hanging connection makes that first line hane-connect gote for black, instead of sente with the solid, so it's better for the endgame (by 2 points).
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ez4u
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Re: Cutting point in 3-3 invasion joseki

Post by ez4u »

Quite and extraordinary exchange!

@Peter Attaboy! :tmbup:
@Ed Well done teacher! :clap:
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21
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Re: Cutting point in 3-3 invasion joseki

Post by PeterPeter »

EdLee has been an excellent and generous teacher on this and other threads, so instead of picking a single post of his to ‘like’, I will say it here: Thank you Ed. :clap:
Regards,

Peter
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EdLee
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Post by EdLee »

Peter, you're very welcome. :mrgreen: You didn't wear me out at all, but it was already something like 4 in the morning,
and I had to get up early today. :-?
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EdLee
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Post by EdLee »

Peter, nice job on comparing the tiger's mouth vs. the connect.
There are probably other good reasons, but I like these: better shape, better eye-space, better yose.
PeterPeter wrote:Probably a basic question, but why was :w20: played here?
You're correct, but it's a good question, and the basics behind it are important,
and it's good you now understand them better. :)
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