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.
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.
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.
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 ...
You will surely agree that Black's marked stone is "alive". However, ...
... after White captured this stone ...
... she is able to stop Black from re-occupying that point with a stone.
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.
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.
+ + + + + + + + + +
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".
Type 7:
All other black stones shall be "alive in seki".
+ + + + + + + + + +
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) !!!
Japanese vs Chinese scoring system
-
Cassandra
- Lives in sente
- Posts: 1326
- Joined: Wed Apr 28, 2010 11:33 am
- Rank: German 1 Kyu
- GD Posts: 0
- Has thanked: 14 times
- Been thanked: 153 times
Re: Japanese vs Chinese scoring system
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Igo Hatsuyōron #120 (really solved by KataGo)
-
RobertJasiek
- Judan
- Posts: 6273
- Joined: Tue Apr 27, 2010 8:54 pm
- GD Posts: 0
- Been thanked: 797 times
- Contact:
Re: Japanese vs Chinese scoring system
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
-
hyperpape
- Tengen
- Posts: 4382
- Joined: Thu May 06, 2010 3:24 pm
- Rank: AGA 3k
- GD Posts: 65
- OGS: Hyperpape 4k
- Location: Caldas da Rainha, Portugal
- Has thanked: 499 times
- Been thanked: 727 times
Re: Re:
Let me see if I understand, abstracting from the questions about assumption.Bill Spight wrote:No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone.
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?
-
Cassandra
- Lives in sente
- Posts: 1326
- Joined: Wed Apr 28, 2010 11:33 am
- Rank: German 1 Kyu
- GD Posts: 0
- Has thanked: 14 times
- Been thanked: 153 times
Re: Japanese vs Chinese scoring system
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.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Igo Hatsuyōron #120 (really solved by KataGo)
-
Cassandra
- Lives in sente
- Posts: 1326
- Joined: Wed Apr 28, 2010 11:33 am
- Rank: German 1 Kyu
- GD Posts: 0
- Has thanked: 14 times
- Been thanked: 153 times
Re: Re:
hyperpape wrote:Let me see if I understand, abstracting from the questions about assumption.Bill Spight wrote:No, but before scoring White can reopen play. Black can play first, but will pass. Then White captures the stone.
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.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Igo Hatsuyōron #120 (really solved by KataGo)
-
Pio2001
- Lives in gote
- Posts: 418
- Joined: Mon Feb 16, 2015 12:13 pm
- Rank: kgs 5 kyu
- GD Posts: 0
- KGS: Pio2001
- Has thanked: 9 times
- Been thanked: 83 times
Re: Japanese vs Chinese scoring system
Guys ! 
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.
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.
-
Cassandra
- Lives in sente
- Posts: 1326
- Joined: Wed Apr 28, 2010 11:33 am
- Rank: German 1 Kyu
- GD Posts: 0
- Has thanked: 14 times
- Been thanked: 153 times
Re: Japanese vs Chinese scoring system
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 ...
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Igo Hatsuyōron #120 (really solved by KataGo)
-
Bill Spight
- Honinbo
- Posts: 10905
- Joined: Wed Apr 21, 2010 1:24 pm
- Has thanked: 3651 times
- Been thanked: 3373 times
Re: Japanese vs Chinese scoring system
Pio2001 wrote:Guys !
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.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
-
hyperpape
- Tengen
- Posts: 4382
- Joined: Thu May 06, 2010 3:24 pm
- Rank: AGA 3k
- GD Posts: 65
- OGS: Hyperpape 4k
- Location: Caldas da Rainha, Portugal
- Has thanked: 499 times
- Been thanked: 727 times
Re: Japanese vs Chinese scoring system
Whoops!Pio2001 wrote:Guys !
The topic opener is 24 kyu, is asking about OGS, and it is his first message on this board
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
.