RobertJasiek wrote:
Cassandra, your discussion on #1:
As far as my personal opinion is concernced, I do not care for #1. I would happily accept one of the following: 1) both alive, 2) both dead, 3) Black alive, White dead, 4) White alive, Black dead. The #1 shape is locally non-terminal anyway.
I do not like your 3) and 4). But OK, a score of 3 points for Black or 7 points for White would be an even stronger motivation than "Seki" to play out the position.
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Since the Japanese professionals chose (1) as their latest judgement, that is what I realize in J2003.
I assess the concluding result "Seki" to be far more important.
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(I do not think though that your general approach is simple.)
May be at least as simple as J2003

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Can you please explain how general your statement "chose 'not alive', because this is the choice that has NO side effect on neighbouring chains, never" is? Is it meant to hold for ALL examples in ALL positions? If so, prove your statement!
I have written "never" and I mean "never".
To explain:
I suppose you will agree to the precondition that "not alive" chains inside opposing "alive" ones will become prisoners.
"
Not alive" is a passive characteristic of a chain. It has an effect on the chain under evaluation only. None of the opposing chains in its neighbourhood will be affected. Remember that "will be taken off the board" is something that is done to the chain, the chain itself remains passive.
"Not alive" does not preemt any evaluation of neighbouring opposing chains (to achieve an intended concluding result). If at least one of these opposing chains ends as "not alive", too, our chain will remain on the board. If all of these opposing chains end as "alive", our chain will be taken off the board. What is done to our chain depends on the evaluation results of the neighbouring opposing chains only.
"
Alive" is an active characteristic of a chain. It potentially affects all neighbouring opposing chains, because it says: "Be aware to become 'alive', else I might take you off the board." "To take something off the board" is actively done to others.
I do not worry about the "alive"-"alive" coexistence of uncapturable chains that are situated in a concluding Seki. Nor about really capturable "dead" stones, which are Nakade inside opposing chains.
The problem arises with opposing capturable chains that are positioned to become a concluding Seki, as in example #1.
If Black's 4-stone chain is evaluated as "alive", it will be become mandatory to have "alive" for White's single stone, too. Else there will be no Seki. The result of the evaluation of one chain determines the (so far unknown) result of the evaluation of another one.
So first there is the (desired) status of White's single stone. Second comes the desperate search for a procedure to achive this (desired) result. There is no independence between procedure and result any more.
And what is even more dangerous: Once you have decided on this very special procedure, it might have side-effects on positions you probably do not want it to have. Had we (uncertain as we were) chosen "not alive", the concluding result would have been the same, and nothing else on the board would be pre-empted.
RobertJasiek wrote:
Your attempt to repeat Chris Dams's proof:
...
I do not consider Chris proof trivial.
May be the attached diagram will help you with the topic.
Or in short:
Let C = A - B
Let D = C + B
It follows D = (A - B) + B = A
I wouldn't call this "proof", but "circular reference".
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2) I modified the intention as slightly as apparently possible and necessary to create J2003 as an otherwise general model. It is not like "I chose what I wanted" but rather like "I chose what makes the greatest sense within the given context".
"I modified the intention" is the kind of "marketing" I would suggest you to avoid

Taking your last sentence, try to start from the end for what I meant with "better marketing".
1) There is the given context.
2) This is the developed rule set.3) Here are the results of the "new" rule set.
4) Here is which results differ from the "old" one (respectively which are better defined).
5) This is why they differ (respectively ...).
6) Suggested principles to heal (most of) the differences.
7) This is why these principles make sense.
Did you read any "I chose" within 1) to 7) ?
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- "collapse of the seki" in the official commentary has to be criticised as not providing explanation because that concept is not a concept of J1989.
Yes, this "concept" makes it difficult to find consistency within the rules.
I thought a lot about the corresponding examples yesterday.
Your "Hypothetical Ko-Pass" is a brilliant idea to simulate "collapse of a Seki" during evaluation. How long had you thought about it ? Despite the 1989 Nihon Kiin results are achieved with its help, be aware that your procedure provides a very one-sided discrimination of the defender.
All of the corresponding examples contain a chain with a Double-Ko (-Seki temporarily) on one side and capturable opponent's stones on the other. Due to the necessary Ko-Passes of the defender (the attacker does not need to make any, I suppose), the Double-Ko remains open until the attacker had been able to capture everyting what he could capture on the other side. This indeed "resolves" the Seki and the Double-Ko as well.
(Might be a more "marketing-oriented" description than many more or less crypical coded move sequences.
)The resulting
effect is the same as with a model, I visualised for me, which does not have a special Ko rule for evaluation. And which by far is not as elegant as your solution.
"If the status of a chain cannot be decided, because the evaluation sequence runs into a cycle, try a second time after taking all dead stones (as found within all the non-cycle evaluations) of the board."
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- A pure text interpretation of J1989 should be tried if anyhow possible while consistent with also all other examples. (I found out though that such a pure text interpretation is inconsistent over the set of all known (relevant) examples.)
I agree. With the text alone, there is not consistent application on the examples possible that matches the "official" results.
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- As far as possible, the officially stated statuses should be recreated with a consistent method that works also for all other known (relevant) examples and that approaches a pure text interpretation of J1989 as closely as otherwise reasonably possible. (I would have to look up my files to check what is recreated. No time for that now.)
You are true, if the aim is the replacement of the Nihon Kiin rules set (as of 1989, taken together with the 1989's intention) with a consistent one, mirroring the 1989's intention.
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Your sample set of principles is insufficient because it ignores professional judgement entirely.
These principles enlighten the scene from a different point of view. This could open the chance to discuss "Does the 2010's intention match the 1989's intention ?" based on a broader foundation of arguments.
Think about "collapse of the Seki", for example.
"Method A within model a (may be the "old" one) gives the same (may be desired) result(s) as
Method B within model b (may be the best consistent one, based on solid research) as
Method C within model c (may be another consistent one, just another point of view) as
Method D within model d (may be another consistent one, not found yet).
Does whatever happens within methods A to D to get the result match the 2010's intention ?"
If the answer is "Yes", we will choose Model b.
It goes without saying that the models' "principles" must be acceptable. Something like "The result could be achieved within my model, if one side plays two moves in a row during evaluation." will be a show-stopper.