Japonese counting

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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

Cassandra wrote: The question is NOT the status of Black's stones, these are dead for sure, as Black cannot prevent their capture. :razz:
You are right Cassandra, my question is not the correct one. Let me rephrase it:
Click Here To Show Diagram Code
[go]$$W White to play
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
My question is now the following (I am not quite sure of the answer):
What is the best play for white, to capture the black stones at the top or to pass in order to avoid losing a point?
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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

jann wrote:I think in J89 the last position needs an extra W move, to prevent B abuse of the pass-for-ko rule (B dead but some W stones too).
That the point Jann. But here is where I am hesitating : I am not sure you can prove some W stones are dead. How do you proceed?
jann wrote:Note though that rule is known to be flawed, there were some old counterexamples for it, and recently lightvector found even more convincing ones. This example is similar.
Interesting Jann. Do you have a link to these recent lightvector's counter examples?
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jann
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Re: Japonese counting

Post by jann »

Gérard TAILLE wrote:I am not sure you can prove some W stones are dead. How do you proceed?
The right side W stones seem dead (J89 only) when B starts by taking the ko next to them, W cannot connect because then B takes the other ko and W has no time to pass for either.
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kvasir
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Re: Japonese counting

Post by kvasir »

I think it goes like this.
Click Here To Show Diagram Code
[go]$$W
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
White: your stones are dead!
Black: yes, btw your stones are dead!
White: I request a resumption on grounds of J89 Article 9 Paragraph 3 !!!
Black: I must oblige!
Click Here To Show Diagram Code
[go]$$B :b3: Pass :w4: Pass
$$ -----------------
$$ | O X . X O 1 O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O 2 O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Black: Your stones are alive, dog gone it!
White: I told you so!
Black: Wait what?!
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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

jann wrote:
Gérard TAILLE wrote:I am not sure you can prove some W stones are dead. How do you proceed?
The right side W stones seem dead (J89 only) if B starts by taking the ko next to them, W cannot connect because then B takes the other ko and W has no time to pass for either.
yes Jann but white has perhaps a defence:
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O X 2 X O 1 O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O 3 O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O . O X . X . |
$$ | . O X X X . . |
$$ | O O O X . . . |
$$ | . O X 4 5 X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Click Here To Show Diagram Code
[go]$$B :b7: pass for ko at the top
$$ -----------------
$$ | O 8 W X . X . |
$$ | . O X X X . . |
$$ | O O O X . . . |
$$ | . O 6 O X X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
I guess it will be the sequence in an "encore" but we are in J89. You can see that the white group at the right has been captured but white as created two new living stones with :w8: and the marked stones. Does that mean that the right white groupe has been captured but is not dead?
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jann
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Re: Japonese counting

Post by jann »

W can save the other half but this is worthless for him. B capturing the right side didn't enable the new W stones, those were possible anyway.
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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

jann wrote:W can save the other half but this is worthless for him. B capturing the right side didn't enable the new W stones, those were possible anyway.
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O B C X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O a O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
That is exactly what is unclear for me.
Both players passed and we are in the confirmation phase.
White proves black stones are dead and black proves that white stones at the right are also dead. As a consequence the eye point a is not surrounded by living stones => a is a dame => all the white stones are in seki with the black stones at the top => the marked points are not controlled by white.
That is my point : "enable the new W stones" is difficult to understand.
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Mike Novack
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Re: Japonese counting

Post by Mike Novack »

kvasir wrote:I think it goes like this.
Click Here To Show Diagram Code
[go]$$W
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
White: your stones are dead!
Black: yes, btw your stones are dead!
White: I request a resumption on grounds of J89 Article 9 Paragraph 3 !!!
Black: I must oblige!
Click Here To Show Diagram Code
[go]$$B :b3: Pass :w4: Pass
$$ -----------------
$$ | O X . X O 1 O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O 2 O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Black: Your stones are alive, dog gone it!
White: I told you so!
Black: Wait what?!
Correct, the white stones are alive and the black stones dead. Gerard, I think you need to look at "double ko". And remember, ko means cannot capture back for ONE turn. Black is dead here because this is not double ko for him (he cannot fill to end either ko because self atari)

Gerard, after that last diagram, what would be black's move 3? Black cannot fill the ko (self atari) and if he takes the ko in the left corner to put white in atari, white 4 takes the other ko to put black in atari <and black is dead>
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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

Mike Novack wrote:
kvasir wrote:I think it goes like this.
Click Here To Show Diagram Code
[go]$$W
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
White: your stones are dead!
Black: yes, btw your stones are dead.
White: I request a resumption on grounds of J89 Article 9 Paragraph 3 !!!
Black: I must oblige!
Click Here To Show Diagram Code
[go]$$B :b3: Pass :w4: Pass
$$ -----------------
$$ | O X . X O 1 O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O 2 O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Black: Your stones are alive, dog gone it!
White: I told you so!
Black: Wait what?!
Correct, the white stones are alive and the black stones dead. Gerard, I think you need to look at "double ko". And remember, ko means cannot capture back for ONE turn. Black is dead here because this is not double ko for him (he cannot fill to end either ko because self atari)
Mike, you are right in normal play but it is not the case here.
Click Here To Show Diagram Code
[go]$$W White to play
$$ -----------------
$$ | O X . X O . O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O . O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
Assume :w1: pass, :b2: pass
If white request resumption of the game black is allowed to play first but here she will simply pass again and, to avoid losing a point white will also pass and the game stops.
Now the confirmation phase begins and if it follows:
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O X . X O 1 O |
$$ | . O X X X O O |
$$ | O O O X O O O |
$$ | . O 2 O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
then because white has not passed for the ko :b1: it will follow
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O X . X . X O |
$$ | 3 O X X X O O |
$$ | O O O X O O O |
$$ | 5 O O O O X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
:w4: pass
and the white stones are all captured
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Cassandra
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Re: Japonese counting

Post by Cassandra »

jann wrote:W can save the other half but this is worthless for him. B capturing the right side didn't enable the new W stones, those were possible anyway.
Click Here To Show Diagram Code
[go]$$B :b7: pass for ko at the top
$$ -----------------
$$ | O 8 W X . X . |
$$ | . O X X X . . |
$$ | O O O X . . . |
$$ | . O 6 P X X X |
$$ | O O O X X X . |
$$ | X X X X . X X |
$$ | . . . . . X . |
$$ -----------------[/go]
:wx: had been captured before, it's part of a snap-back.

White's captured stones in the upper right are alive.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
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Cassandra
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Re: Japonese counting

Post by Cassandra »

Gérard TAILLE wrote:That is my point : "enable the new W stones" is difficult to understand.
In the original text,

"生じうる"

is the conjunctive form of

"生じる",

which is "come into being".

"生じうる" => "can come into being".

Probably this helps.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
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kvasir
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Re: Japonese counting

Post by kvasir »

Gérard TAILLE wrote:
Mike Novack wrote:Correct, the white stones are alive and the black stones dead. Gerard, I think you need to look at "double ko". And remember, ko means cannot capture back for ONE turn. Black is dead here because this is not double ko for him (he cannot fill to end either ko because self atari)

Mike, you are right in normal play but it is not the case here.

The J89 rules are flawed in various ways, for example there is no mentioning of an arbitrator or adjournment, but the preamble does says this:
"These rules must be applied in a spirit of good sense and mutual trust between the players."

In this case black is claiming that white's stones are dead because they can be captured in a ko but refuses to start the ko even though this does not reduce his territory (it is dame since it is not surrounded by a living group, black's group is dead). Not many people are going to agree that this is "in spirit of good sense".

You could go ahead and try this in a tournament to find out if the referees are amused.
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Re: Japonese counting

Post by RobertJasiek »

When I tried a J89 rules dispute about dame creating seki in 1994, the referee correctly decided that WAGC Rules were being used in that tournament;) Saijo, one of the two major J89 writers, watched and became aware that they had overlooked this dame side effect during rules design.
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Re: Japonese counting

Post by kvasir »

In article 10 it says the following:
"After agreement that the game has ended, each player removes any opposing dead stones from his territory as is, and adds them to his prisoners."

Basically if one takes it literally there is also a problem of how to count a game if dead groups can be surrounded by dead groups.

RobertJasiek wrote: When I tried a J89 rules dispute about dame creating seki in 1994, the referee correctly decided that WAGC Rules were being used in that tournament;) Saijo, one of the two major J89 writers, watched and became aware that they had overlooked this dame side effect during rules design.
There is just no way to proceed if one takes this text completely literally.
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Gérard TAILLE
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Re: Japonese counting

Post by Gérard TAILLE »

RobertJasiek wrote:When I tried a J89 rules dispute about dame creating seki in 1994, the referee correctly decided that WAGC Rules were being used in that tournament;) Saijo, one of the two major J89 writers, watched and became aware that they had overlooked this dame side effect during rules design.
To avoid dame issue here is an easier position:
Click Here To Show Diagram Code
[go]$$W
$$ -----------------
$$ | O X . X . O . |
$$ | . O X X X O O |
$$ | O . O X O . O |
$$ | O O O X X O . |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]
Do white has to add a move before passing and stoping the game?

OC, if white decide to pass then, in confirmation phase, black will play:
Click Here To Show Diagram Code
[go]$$B Confirmation phase
$$ -----------------
$$ | O X . X 5 O 7 |
$$ | 1 O X X X O O |
$$ | O 2 O X O 3 O |
$$ | O O O X X O 4 |
$$ | X X O O O O O |
$$ | . X X X X X X |
$$ | . . . . . . . |
$$ -----------------[/go]
:w6: pass
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