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Re: Question about Eyes in Seki Under Japanese Rules

Posted: Wed Aug 19, 2020 10:14 am
by Bill Spight
jaeup wrote:
Bill Spight wrote:OC, ishi in Japanese can be singular or plural, and the Japanese rules do not include words like string, chain, dragon or group. To the extent to which that causes ambiguity or confusion, well, the Japanese can be inscrutable even to themselves. ;)
Right. You understand the subtlety of the situation very well. Because of such ambiguity, its direct translation into English is simply impossible. The translator (James Davies, right?) ended up using the word "group", but I cannot agree with such a style change. The actual rule always talks about "stone(s)", such as "this stone is a seki stone". It never says like "this group is alive by seki".

Fortunately, the structure and practice of the Korean language allows one to make an almost perfect direct translation of the Japanese rule. Of course, unfortunately, after finishing the translation, I still cannot decide if a specific sentence talks about one stone each or a collection of stones. :)
Davies used group for a set consisting of a single stone or of rookwise connected stones of the same color. Unfortunately, group was already used in English for a not well defined collection of stones of the same color. Be that as it may, Davies removed the ambiguity of the Japanese ishi for the question of having a liberty. :)

Re: Question about Eyes in Seki Under Japanese Rules

Posted: Wed Aug 19, 2020 10:40 am
by jann
I doubt adding seki as an exception (to exclude territory) is the right approach. It seems more robust to define territory first (transformable to pass-alive). Then dead stones are only those in territory, and seki is unnecessary.

Re: Question about Eyes in Seki Under Japanese Rules

Posted: Wed Aug 19, 2020 9:49 pm
by Bill Spight
jann wrote:I doubt adding seki as an exception (to exclude territory) is the right approach. It seems more robust to define territory first (transformable to pass-alive). Then dead stones are only those in territory, and seki is unnecessary.
It would be interesting to see such rules. :)

I suspect that if it were easy to make such rules, the Japanese and Koreans would have done so already. Humans are good with handling exceptions, so perhaps the easiest rules to craft and also to understand are those that say, thus and such points are territory, with the following exceptions. Anyway, it would be interesting to see rules that do not take that approach.

Re: Question about Eyes in Seki Under Japanese Rules

Posted: Wed Aug 19, 2020 10:54 pm
by Cassandra
Bill Spight wrote:
jann wrote:I doubt adding seki as an exception (to exclude territory) is the right approach. It seems more robust to define territory first (transformable to pass-alive). Then dead stones are only those in territory, and seki is unnecessary.
It would be interesting to see such rules. :)
Perhaps Robert does have a set of these?

By the way, in Japanese (-style) rules, I think that it will be difficult to overcome the obstacle that there are three types of groups at the end of the game ...
-- Groups that have two eyes (including e.g. the snap-back subset), and so cannot be captured.
-- Groups that do not have two eyes, but cannot / will not be captured ("usually" called "seki"-groups).
-- Groups that do not match one of the definitions above ("usually" called "dead" groups).
... and that a definition of territory is needed
-- e.g. points enclosed by two-eyed groups.

It would be possible to choose the definition of "two-eyed group" and "seki group", and to NOT define "dead" groups (which are just the rest). And to NEVER mention "neutral points".

However, if you wanted to define "territory", but not "seki-group", you would have to incorporate something (that jann does not want to call "exception") in your set of conditions for defining "territory".

Re: Question about Eyes in Seki Under Japanese Rules

Posted: Thu Aug 20, 2020 12:11 am
by RobertJasiek
Bill Spight wrote: I suspect that if it were easy to make such rules, the Japanese and Koreans would have done so already.
Once hypothetical play was defined, it was easy to make such rules:

http://home.snafu.de/jasiek/sj.html

Since it is easy and the Japanese and Koreans do not use such or similar, on the high level easy rules, they want unnecessarily complicated rules.

Re: Question about Eyes in Seki Under Japanese Rules

Posted: Thu Aug 20, 2020 3:18 am
by jann
Cassandra wrote:However, if you wanted to define "territory", but not "seki-group", you would have to incorporate something (that jann does not want to call "exception") in your set of conditions for defining "territory".
I don't see why. What I wrote above seems to work without this:
jann wrote:It seems more robust to define territory first (transformable to pass-alive). Then dead stones are only those in territory, and seki is unnecessary.
BTW, I think the only reason to exclude territory in sekis is implicit in this approach. Otherwise explicitly excluding them seems pointless and unnecessary complication (burden for no gain). So defining seki in either way seems a bad idea.