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 Post subject: Re: Japanese vs Chinese scoring system
Post #21 Posted: Tue Dec 20, 2016 9:01 am 
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I would not call this effect a "flaw". It's simply a consequence of the inner philosophy of Japanese rules.

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


This position in the corner is a seki. But Black can gain 8 points before the end of the game.

This kind of "unbalance" cannot be helped.

One consequence of the inner philosophy of Chinese rules is the possibility to have points inside a seki (often also combined with some kind of "unbalance").

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Post #22 Posted: Tue Dec 20, 2016 9:17 am 
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Indeed, I don't think the requirement to 'capture dead stones in seki' to get points for them is really a problem in Japanese rules. What is a downside (but not so bad I'd call it a flaw) is that if players aren't aware of that and have passed to finish the game then they can't go back and take the stone(s) to get the points once made aware they need to in order to get the points (DrStraw may know this already so would have captured the stones before passing in his game). Of course a kind player may break the rules and allow their opponent to do so, but AGA rules with their 'resume play to sort out problems' approach written into the rules is better IMO. What I would call a flaw is the fake seki Bill posted about, which I seem to recall the professional author of the J1989 rules himself admitted was an unintended bad consequence of how he had written those rules.

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Post #23 Posted: Tue Dec 20, 2016 10:22 am 
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Uberdude wrote:
What I would call a flaw is the fake seki Bill posted about, which I seem to recall the professional author of the J1989 rules himself admitted was an unintended bad consequence of how he had written those rules.

Ah, I see now what you meant.

Japanese rules have a strict "local" context, so the J89 rules creator(s) lost the "long-range weapon" ko out of sight. They simply did not consider that occupying dame of an independently alive group might create ko threats for the opponent that were not available before.

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Post #24 Posted: Tue Dec 20, 2016 10:26 am 
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Quote:
What is a downside (but not so bad I'd call it a flaw) is that if players aren't aware of that and have passed to finish the game then they can't go back and take the stone(s) to get the points once made aware they need to in order to get the points


I never let the rules minutiae get between me and a game so I may not have the right handle on what you are describing, but as I recall the latest Japanese rules you can resume the game after the pass suspension. The only impediment is that you have to let the opponent play first. But that is presumably not normally a problem in a seki.

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Post #25 Posted: Tue Dec 20, 2016 11:35 am 
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Cassandra wrote:
DrStraw wrote:
It is clearly seki regardless but under Japanese rules white will capture one stone, ...

If the position shown is the FINAL position of the game, then the result / score is jigo.

If White wanted to win the game, she should have captured Black's single stone earlier.

Black's single stone is not situated inside White's territory, as White does not have any territory. Therefore, this stone cannot be taken of the board after the end of the game to be counted as a prisoner.


No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone. :)

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Post #26 Posted: Tue Dec 20, 2016 11:45 am 
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Bill Spight wrote:
No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone. :)

This is a valid strategy for White, worth considering during the agreement procedure after the stop of the game.

However ...

Cassandra wrote:
If the position shown is the   F I N A L   position of the game, ...


... nothing can be done after the end of the game ;-)

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Post #27 Posted: Tue Dec 20, 2016 12:30 pm 
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For really understanding the Japanese 1989 Rules, see http://home.snafu.de/jasiek/j1989c.html

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Post #28 Posted: Tue Dec 20, 2016 2:19 pm 
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RobertJasiek wrote:
For really understanding the Japanese 1989 Rules, see http://home.snafu.de/jasiek/j1989c.html

TL;DR
:roll:

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Post #29 Posted: Wed Dec 21, 2016 1:34 am 
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Uberdude wrote:
Otherwise known as strictly following the rules (and I thought you were a fellow pedant). If following the rules gives results that feel wrong to people who know how to play Go then there are problems with the rules, which is why many people have criticised and tried to improve upon the J1989 rules (e.g. Bill Spight, Robert Jasiek). It is not an easy task though. Of course most people won't be a stickler over these things, but if you ask Csaba Mero I'm sure he'll tell you it's better if rules don't have flaws like this (he had a famous dispute with Robert under Ing rules).


Fortunately this moment in Go rules history was preserved for prosperity:

https://www.youtube.com/watch?v=zRdYQJqKls8


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Post #30 Posted: Wed Dec 21, 2016 7:14 am 
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dust wrote:
Fortunately this moment in Go rules history was preserved for prosperity:

https://www.youtube.com/watch?v=zRdYQJqKls8

With a cameo by a young Ilya Shikshin.

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 Post subject: Re: Japanese vs Chinese scoring system
Post #31 Posted: Wed Dec 21, 2016 7:58 am 
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Here follow some additional thoughts (largely based on 囲碁ルールの研究–理論と歴史 by 関口 晴利; "Research on Go Rules – Theory and History" by Sekiguchi Harutoshi, ISBN 978-4286031422) about the challenge to phrase an unambiguous rules text. To keep it relatively simple, a discussion on the application for complicated large formations with (several) open ko-shapes is not included.

What do we "really" want by using Japanese style rules for eventually scoring the game ?
First we have to decide on "life and death", thereafter, we can decide on "prisoners" and "territory".

+ + + + + + + + + +

Let us start with groups that are "independently alive".

Type 1:
Probably we would like to start with considering a group of black stones to be "alive" that surrounds two (or more) empty points of the board, which are "forbidden" for White.

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

Usually, these "forbidden-for-White" points are called black eyes, so let us call this type of life "2EL" (= two-eyes-life).

As a matter of course, groups of type 1 "cannot be captured". However, you will surely know that type 1 is not a unique application case for "cannot be captured".


Type 2:
Not everything on the board is yet solidly connected, so we have to include black groups that – even if White plays first – can be transformed into type 1, explained above, by using alternative play.

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

Click Here To Show Diagram Code
[go]$$W
$$ +-------------
$$ | . X 2 X O .
$$ | X X 1 X O .
$$ | O X X O O .
$$ | O O O O . .
$$ | . . . . . .[/go]

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


Type 3:
Not everything on the board is safe from being captured by the opponent, so we have to include a type of black groups that is mainly known from the "snap-back"-issue. Even if a black stone (phrasing for a group would be more tricky) has been captured, it is said to be of the "2EL"-type, if Black can transform the before occupied point into an integral part of a black type 1 or type 2 group through alternative play.

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

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

Click Here To Show Diagram Code
[go]$$W
$$ +-------------
$$ | O O X X . X .
$$ | O 2 O X X X X
$$ | X O O O O O O
$$ | X X O . . . .
$$ | . X O . . . .
$$ | X X O . . . .
$$ | . X O . . . .[/go]

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

As a matter of course, in the overwhelming majority of cases this captured black stone will be replaced by a permanent stone of the same color. However, there are exceptions ...

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

You will surely agree that Black's marked stone is "alive". However, ...

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

... after White captured this stone ...

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

... she is able to stop Black from re-occupying that point with a stone.

Click Here To Show Diagram Code
[go]$$Wm5 W 7, 9 = pass
$$ +-----------------
$$ | 6 1 4 X X . X O .
$$ | X 2 X X X X X O .
$$ | X X X O O O O O .
$$ | O O O O . . . . .
$$ | . . . . . . . . .[/go]

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

Effectively, this point will become a "forbidden-for-White"-point, i.e. an eye.

"... transform ... into an integral part of a type 1 or type 2 group" might be replaced by "... re-occupied by a black stone or turned into a point that is forbidden for White".


+ + + + + + + + + +

Another cluster of groups consists of those groups which are not part of "2EL", but are "alive in seki".

Please note that this second type of "life" is needed to get rid of the usage of "dame". Quite obviously, the authors of the J89 rules did not want to do so.


Type 4:
The simple case of "life in seki" ("LIS") contains black groups that – even if White plays first – can be prevented by Black from being captured by White by alternative play.

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

Click Here To Show Diagram Code
[go]$$W
$$ +-----------------
$$ | . X O 2 X O . O
$$ | X X O 1 X O O .
$$ | . X O O O X O O
$$ | X X X X X X X O
$$ | O O O X . X . X
$$ | . . O O X X X .[/go]

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


Type 5:
The challenging case (not very relevant for practical use) covers black groups that can be captured by White, but where after at least one point of the before occupied area can be transformed into an integral part of a black type 1 or type 2 group.

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

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

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

Click Here To Show Diagram Code
[go]$$W
$$ +-------------
$$ | . 7 X O . .
$$ | 6 X 5 O . .
$$ | X O O O O O
$$ | X X X X O .
$$ | . X . X O .
$$ | X X X X O .[/go]

Click Here To Show Diagram Code
[go]$$W
$$ +-------------
$$ | . O . O . .
$$ | X Y O O . .
$$ | X O O O O O
$$ | X X X X O .
$$ | C X C X O .
$$ | X X X X O .[/go]


+ + + + + + + + + +

Last but not least, "death" is lurking around the corner for groups that are neither of type "2EL" nor of type "LIS".

Type 6:
Black stones that are located inside an area that is surrounded by a white "2EL" group (and which might contain further white "2EL" stones or groups") are said to be "dead stones".

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


Type 7:
All other black stones shall be "alive in seki".

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


+ + + + + + + + + +

For scoring, "dead stones" are taken from the board and counted as prisoners for the opponent. "Territory" is the amount of unoccupied points that are surrounded by "2EL" groups.

No reference to "dame" is needed any longer.
However, it is absolutely necessary to check the exact formulation of the phrased rules (if anyone wanted to do so, based on the thoughts above) to undesirable side effects (e.g. the complex open ko shapes mentioned in the very beginning) !!!

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 Post subject: Re: Japanese vs Chinese scoring system
Post #32 Posted: Wed Dec 21, 2016 10:06 am 
Tengen

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Cassandra wrote:
"Research on Go Rules – Theory and History" by Sekiguchi Harutoshi [...]
"... transform ... into an integral part of a type 1 or type 2 group" might be replaced by "... re-occupied by a black stone or turned into a point that is forbidden for White".


The book was published in 2007 and his description is weaker than mine of 2004 with local-2 and capturable-2 in my Japanese 2003 Rules v35a: http://home.snafu.de/jasiek/j2003.html

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Post #33 Posted: Wed Dec 21, 2016 10:27 am 
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Bill Spight wrote:
No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone. :)
Let me see if I understand, abstracting from the questions about assumption.

In the 4x4 game, if white captures, there a dame that can't be filled between the white and black stones, so it remains seki, and neither side gets points. However, white has a point for his capture of the black stone?

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Post #34 Posted: Wed Dec 21, 2016 10:39 am 
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RobertJasiek wrote:
Cassandra wrote:
"Research on Go Rules – Theory and History" by Sekiguchi Harutoshi [...]
"... transform ... into an integral part of a type 1 or type 2 group" might be replaced by "... re-occupied by a black stone or turned into a point that is forbidden for White".


The book was published in 2007 and his description is weaker than mine of 2004 with local-2 and capturable-2 in my Japanese 2003 Rules v35a: http://home.snafu.de/jasiek/j2003.html


Dear Robert,

Cassandra wrote:
... (largely based on ...


does not imply that everything that can be read in my posting above can also be found in the referenced book (to be honest, I tried to translate only a small portion it).

I would like to assume that the author did not intend to include every esoteric application case in his rules draft.

I would also like to assume that the author concentrated on Japanese and Chinese history.

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Post #35 Posted: Wed Dec 21, 2016 10:40 am 
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hyperpape wrote:
Bill Spight wrote:
No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone. :)
Let me see if I understand, abstracting from the questions about assumption.

In the 4x4 game, if white captures, there a dame that can't be filled between the white and black stones, so it remains seki, and neither side gets points. However, white has a point for his capture of the black stone?

Yes, indeed.

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Post #36 Posted: Wed Dec 21, 2016 10:49 am 
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Guys ! :o
The topic opener is 24 kyu, is asking about OGS, and it is his first message on this board !

The japanese 1989 rule is not even used on OGS. By checking "japanese", you're just telling the software not to count neutral intersections and not to forbid repetitions...
I'm not even sure that it properly counts seki. KGS sometimes counts eyes in seki.


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Post #37 Posted: Wed Dec 21, 2016 10:54 am 
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RobertJasiek wrote:
... description is weaker than mine ...

What do you mean with "weaker" ?

For determining the status of capturable black stones (either to become "alive" or "alive in seki"), the only relevant aspect is whether White can become the owner of ALL before occupied points.

White cannot become the owner, if
-- at least one of these points can be occupied with a permanent black stone, or
-- at least one of these points can be turned into a black eye.

From Black's point of view, you can also combine these two issues into only one case:
-- Black becomes the owner of at least one of the points that his captured group occupied before.

Kind of application might be a matter of taste ...

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Post #38 Posted: Wed Dec 21, 2016 11:40 am 
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Pio2001 wrote:
Guys ! :o
The topic opener is 24 kyu, is asking about OGS, and it is his first message on this board !

The japanese 1989 rule is not even used on OGS. By checking "japanese", you're just telling the software not to count neutral intersections and not to forbid repetitions...
I'm not even sure that it properly counts seki. KGS sometimes counts eyes in seki.


In that case, tell him to use AGA/Chinese scoring. :)

Which I pretty much advised, unless his opponent can help him.

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Post #39 Posted: Wed Dec 21, 2016 11:45 am 
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Pio2001 wrote:
Guys ! :o
The topic opener is 24 kyu, is asking about OGS, and it is his first message on this board
Whoops! :oops:

Anyway, I think Ed was right, and Bill was right too: just play whatever people play where you are. It tends not to matter, and when it does, it's typically just games that are decided by a few points.

And if you like arguing about technical things, come back to talk more about scoring systems ;).

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