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 Post subject: How does white win the capturing race?
Post #1 Posted: Wed Aug 07, 2019 10:42 pm 
Lives with ko

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This is another example from 321go:

Click Here To Show Diagram Code
[go]$$B
$$ | . . . , . . . . . , .
$$ | . . . . . . . . . . .
$$ | . O . O O O . . . . .
$$ | O X O X . . . . . . .
$$ | . X . X O O . . . . .
$$ | X X X X . . . O . . .
$$ | . X X O O O O . . , .
$$ | O O O X . . X X X . .
$$ | . O . X . X . . . . .
$$ | . O . . . . . . . . .
$$ +----------------------[/go]

White to play.
"Can white win the capturing race?"
It is multiple choice.
The answer is "yes".

I'm not talking about the black D2/3 group.
I think it is easy for white to get that one (true?).
It probably makes sense, so white has the left bottom corner.

But at first I thought this capture race was about the black B4 etc. group.
There, I've not been able to find a way for white to win.
It is very close, but white does not win.
Counting liberties, they look equal.
White has an eye, plus is quite strong on A8, C8 (I think, because A9, C9 are protected, though A6, C6 will take white more moves to kill).

So, if the exercise is/was not talking about the bottom left corner, is there a solution how white can kill the bigger black group in a capturing race??

(It would get white more points attacking that group, wouldn't it?)

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 Post subject: Re: How does white win the capturing race?
Post #2 Posted: Wed Aug 07, 2019 11:04 pm 
Gosei
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Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , .
$$ | . . . . . . . . . . .
$$ | . O 5 O O O . . . . .
$$ | O X O X 1 . . . . . .
$$ | . X 7 X O O . . . . .
$$ | X X X X 3 . . O . . .
$$ | . X X O O O O . . , .
$$ | O O O X . . X X X . .
$$ | 6 O 2 X . X . . . . .
$$ | . O 4 . . . . . . . .
$$ +----------------------[/go]


Black can't atari White, otherwise it would be a self-atari, so plays :b8: elsewhere. I reset the move counter,

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


( :b2: is somewhere else) so White can indeed capture Black.

Of course, :w1: and :w3: in the last diagram are generally never played.


This post by jlt was liked by: Bill Spight
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 Post subject: Re: How does white win the capturing race?
Post #3 Posted: Wed Aug 07, 2019 11:33 pm 
Honinbo

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Jika, please make diagrams to show what you are talking about. You did not find a way for White to win the capturing race, but what did you find? It may take more than one diagram, but that way we can better understand what you are thinking, and help you out. :) In addition, when you make diagrams you may see things that you did not see before. :)

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 Post subject: Re: How does white win the capturing race?
Post #4 Posted: Thu Aug 08, 2019 10:23 pm 
Lives with ko

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@jlt:

Thank you!

My sequence was

Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , .
$$ | . . . . . . . . . . .
$$ | 7 O 5 O O O . . . . .
$$ | O X O X 3 . . . . . .
$$ | . X . X O O . . . . .
$$ | X X X X 1 . . O . . .
$$ | 8 X X O O O O . . , .
$$ | O O O X . . X X X . .
$$ | 6 O 2 X . X . . . . .
$$ | . O 4 . . . . . . . .
$$ +----------------------[/go]


I was so busy with white 7 ("I need to protect there first before I can take A6") that I didn't see it was not necessary.

With white 7 black 8 black was ahead.

@Bill:
I'm sorry!

Making a diagram takes me long (I set up the position on a board, then create it in the diagrammer, and some functions the diagrammer has do not work with my browser (FF 68.0.1).

I played out the exercise on a board at least 10 times (with white capturing black 6 and without).
But I never realized that I don't have to make white 7 if the moves are in the right order.

(Sorry, how does one create the numbered stones in text? [go] Tags did not work for that.)

So, while seeing a situation is very often helpful (or I would be bothering you with 5 questions a day), apparently it does not prevent me from totally overlooking a good variant.

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 Post subject: Re: How does white win the capturing race?
Post #5 Posted: Thu Aug 08, 2019 10:43 pm 
Judan

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Jika wrote:
(Sorry, how does one create the numbered stones in text? [go] Tags did not work for that.)


There are shortcuts in the smiley panel to left of post text box, or make like this:
Code:
:w1: :b4: :w45:


:w1: :b4: :w45:

Also if you quote someone else's post (quote button at bottom of each post) you can see the markup which made it.


This post by Uberdude was liked by: Jika
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 Post subject: Re: How does white win the capturing race?
Post #6 Posted: Thu Aug 08, 2019 11:29 pm 
Honinbo

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Jika wrote:
@jlt:

Thank you!

My sequence was

Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , .
$$ | . . . . . . . . . . .
$$ | 7 O 5 O O O . . . . .
$$ | O X O X 3 . . . . . .
$$ | . X . X O O . . . . .
$$ | X X X X 1 . . O . . .
$$ | 8 X X O O O O . . , .
$$ | O O O X . . X X X . .
$$ | 6 O 2 X . X . . . . .
$$ | . O 4 . . . . . . . .
$$ +----------------------[/go]


I was so busy with white 7 ("I need to protect there first before I can take A6") that I didn't see it was not necessary.

With white 7 black 8 black was ahead.

@Bill:
I'm sorry!


Nothing to be sorry about. Nice diagram. :)

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

Visualize whirled peas.

Everything with love. Stay safe.


This post by Bill Spight was liked by: Jika
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 Post subject: Re: How does white win the capturing race?
Post #7 Posted: Fri Aug 09, 2019 5:53 am 
Lives in sente

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Jit
The general concept to learn from this was "eye vs no-eye"

Because white has an eye, the point A4 is a liberty for white but not a liberty for black when you count liberties. Once the black group above is down to just one liberty besides A4 the white group cannot be captured. You were thinking "how many moves for white to capture black when the real problem was how many moves to reduce the black liberties to one (besides A4) because at that point white cannot be captured so black dies.


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 Post subject: Re: How does white win the capturing race?
Post #8 Posted: Fri Aug 09, 2019 6:45 am 
Honinbo

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Jika wrote:
@jlt:

Thank you!

My sequence was

Click Here To Show Diagram Code
[go]$$W
$$ | . . . , . . . . . , .
$$ | . . . . . . . . . . .
$$ | 7 O 5 O O O . . . . .
$$ | O X O X 3 . . . . . .
$$ | . X . X O O . . . . .
$$ | X X X X 1 . . O . . .
$$ | 8 X X O O O O . . , .
$$ | O O O X . . X X X . .
$$ | 6 O 2 X . X . . . . .
$$ | . O 4 . . . . . . . .
$$ +----------------------[/go]


I was so busy with white 7 ("I need to protect there first before I can take A6") that I didn't see it was not necessary.

With white 7 black 8 black was ahead.

@Bill:
I'm sorry!

Making a diagram takes me long (I set up the position on a board, then create it in the diagrammer, and some functions the diagrammer has do not work with my browser (FF 68.0.1).

I played out the exercise on a board at least 10 times (with white capturing black 6 and without).
But I never realized that I don't have to make white 7 if the moves are in the right order.

(Sorry, how does one create the numbered stones in text? [go] Tags did not work for that.)

So, while seeing a situation is very often helpful (or I would be bothering you with 5 questions a day), apparently it does not prevent me from totally overlooking a good variant.


Your sequence is very reasonable, and I can see why you thought the way that you did. As you’ve seen, the order of taking away liberties can make a difference (your :w7: isn’t needed if you switch the order).

Doing more problems like this one will sharpen your ability to see the right order in a sequence. You overlooked a possibility today, but when you come back and see this post in a few months, you’ll wonder how you didn’t see the right answer immediately. Because you’re getting stronger.

Keep up the good work — I enjoy your posts!

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be immersed


This post by Kirby was liked by 2 people: Bill Spight, Jika
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 Post subject: Re: How does white win the capturing race?
Post #9 Posted: Fri Aug 09, 2019 11:54 pm 
Lives with ko

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@Uberdude:
Thank you, I didn't see those!

@Mike:
You are right that it is in a chapter "eye vs. no eye".

@Kirby:
Thank you :D

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