What do you mean Cassandra, my position above is "finished" isn'it ?

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | O X 1 X . O . |
$$ | . O X X X O O |
$$ | O . O O X X O |
$$ | O O O . O X O |
$$ | X X O O X X O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

No, it isn't.

Click Here To Show Diagram Code

[go]$$W
$$ -------------------
$$ | X O X . X O . .
$$ | X O X X X O . .
$$ | 1 O . X O O . .
$$ | O O X X O . . .
$$ | X X O O O O O O
$$ | . X X X X . . .
$$ | . . . . X . . .
$$ | . . . . X . . .[/go]

As well as this.

You are trying to create examples on the basis of a rule, from which is already known that it does not fulfill its intended purpose, not even within J89.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

I think I agree with this statement, if I understand it.

I would use different words, I'd talk about strategy during ordinary play, but during confirmation/analysis play I would use words like "deduction", "reasoning" or "arguments" instead of "hypothetical strategy". This is because I don't think it is "strategy" if everyone is supposed to reach the same conclusion.

I may also be misunderstanding something that was said.

I think I am about to stop following this thread, it is really all over the place in terms of the topic now.

Hypothetical strategy is part of deduction. Posing analysis questions, such as "Is this string alive?", is another part of deduction. Therefore, the word deduction does not substitute the term hypothetical strategy.

Ko rules etc. aside, I have chosen the term hypothetical strategy well because it is almost the same as strategy. Strategy applies to a position before successive passes while hypothetical strategy applies to a position created by successive passes.

I have defined hypothetical strategy in my Japanese 2003 Rules and my Ko research paper. Deriving the definition of strategy as a formal concept is trivial. Note that I have not been the first to define strategy; other game theorists did it earlier in different notation but with essentially the same contents. Needless to say, informal use of the word strategy differs and often refers to higher level strategic concepts while the formal term refers to the low level of decision-making like that of tactical reading.

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | O B . B . O . |
$$ | . O B B B O O |
$$ | O . O O B B O |
$$ | O O O . O B O |
$$ | X X O O B B O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

What is your reasonning to conclude this game is not finished?

My reasonning is the following:
By normal play, the black stones are dead, even if black plays first as shown in the following diagram:

Click Here To Show Diagram Code

[go]$$B normal play hypothesis
$$ -----------------
$$ | O B . B . O . |
$$ | 1 O B B B O O |
$$ | O 2 O O B B O |
$$ | O O O . O B O |
$$ | X X O O B B O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

As a consequence, as white, I would like to stop the game without adding a play (I mean without losing a point).
Here is my point: before really passing, I calculate what would happen in the confirmation phase and I discover it is a seki according to the rule.
With this analysis OC I do not pass and add a move.

Yes the game is not finished but in order to discover the game is not finished you have to analyse the position by assuming two passes. That is exactly what I suggested : analysing the above position assuming the game is stopped and read the consequences.

BTW the best move to add for white is this one

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | O X . X . O . |
$$ | 1 O X X X O O |
$$ | O . O O X X O |
$$ | O O O . O X O |
$$ | X X O O X X O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

That way black cannot make any ko threat : even if black plays several moves white can always pass.

Ok, Robert, I get it. We do disagree about what is the major flaw of J89.

When I said:

"This is the major flaw of J89 in my mind: Neither player is required to do anything, they can disagree about every group and refuse to play more moves by passing when the game resumes and never agree to end the game."

It could also be taken as criticism of your J03, which was not intended because I think there is a difference between what is needed for basic rules and what is needed for complete rules for a game as adopted by an organization like NHK. It is also important in this regard that J89 has many unexpected results that players will refuse to accept and referees and appeals commissions are likely to side with the player that contradicts the rules in some such cases.

In the end it is unclear if J89 are the actual rules of play anywhere, which is a major flaw that I attribute largely to the presentation and omissions in the J89 text.

Even you added a move, but still claim that the position was NOT unfinished?

In principle, you are looking for extensions of life-and-death example 9, which examines an unfinished position, too.
=> Let's assume that White must not recapture any ko, and see whether White will die or not.
=> If White dies, she will have to add a move to avoid seki.

Try taking White's seven stones at the left in life-and-death example 16 off the board, and you will realise that Article 7, 2. does not even work inside J89 as intended.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

You did not take my point Cassandra.
I wrote:
"Here is my point: before really passing, I calculate what would happen in the confirmation phase and I discover it is a seki according to the rule."

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | O X . X . O . |
$$ | . O X X X O O |
$$ | O . O O X X O |
$$ | O O O . O X O |
$$ | X X O O X X O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

What does that mean? I never claimed the game is finished (BTW I guess "stopped" would be a better wording). I only calculated, by using confirmation phase, what would be the result IF I decided to finish (stop) the game. Seing a seki according to the rule then I continue the game and I add a move to avoid it.
Yes I had to run (in my head) the confirmation phase from the position above but that does not mean that I finished the game. On contrary, after my analysis I decide to add a move.
At the time the position above really appear I do not know if I will stop the game or not and the answer will be given by the analysis of the position by the confirmation phase (in my head because the game is not yet stopped).
That way you see how it is relevant to be sure of the result of the confirmation phase in the position above.


What is is your point? OC, in normal play the seven white stones cannot be capture due to a triple ko but as sson as both players pass then white stones are dead through confirmation phase. The only way for white to avoid losing her stones is to continue the game for ever by using an infinite number of resumption. Eventually I hope the referee will stop these resumptions and all white stones will be declared dead. Am I wrong?

Seems so

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . O O . Q . Q X . X O . O X . . . . . |
$$ | O X X Q Q Q Q X X O O O O X . . . . . |
$$ | X X . X X X Q X O . O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

What is the status of White's group?

+ + + + + + + + + + + + +

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | 1 O O . O . O X 2 X O . O X . . . . . |
$$ | O X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X O 3 O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | X O O . O . O X O b O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X a X O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

pass for a
pass for b

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | X O O . O . O X O 7 O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X 6 X O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | X O O . O . O X a X O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X O b O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

pass for a
pass for b

... ad infinitum ...

+ + + + + + + + + +

Variation:

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | X O O 5 O . O X O ? O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X . X O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

The shadowed point is taboo for Black.

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | X . 6 X O . O X O ? O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X . X O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$Bm7
$$ +---------------------------------------+
$$ | X 1 O 3 O . O X O ? O . O X . . . . . |
$$ | . X X O O O O X X O O O O X . . . . . |
$$ | X X . X X X O X 2 X O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X 4 X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

+ + + + + + + + + + + +

Conclusion:

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . O O . Q . Q X . X O . O X . . . . . |
$$ | O X X Q Q Q Q X X O O O O X . . . . . |
$$ | X X . X X X Q X O . O X X X . . . . . |
$$ | . . . , X O X X X O O X . . . , . . . |
$$ | . . . . X O X . X O X X . . . . . . . |
$$ | . . . . X O X X O X X . . . . . . . . |
$$ | . . . . X O O O O . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

is alive.

It should be evident that life-and-death examples 17 and 18 are mistaken for the same reason.
It is impossible to capture anything attached to a double-ko that has MORE THAN THREE liberties.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Oops I am very surprised to see you act as these western players who do not really understand what is behind the written rule.
You simply exploit what is strickly written even if the result looks stupid.

Let's take the following position:

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | . X . X O X . |
$$ | X X X O O X X |
$$ | O X O O X X . |
$$ | . O . O O X . |
$$ | O O O O O X . |
$$ | X X X X X X . |
$$ | . X . . . . Q |
$$ -----------------[/go]

what is the status of ?
According to the loop you highlited in your last post is a living stone. Do you really believe a japonese referee will declare this stone alive?
There are a lot of flaws in the rule. Here the way to handle a loop in the confirmation phase is simply not defined and common sense must apply.

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | O X . X . O . |
$$ | . O X X X O O |
$$ | O . O O X X O |
$$ | O O O . O X O |
$$ | X X O O X X O |
$$ | . X X O O O . |
$$ | X . X X X O O |
$$ -----------------[/go]

BTW I am also surprised to see you conclude here it is a seki while the common sense tells us black is dead! Remember that, in normal play, black is dead even if she plays first.

Maybe we need a Japanese speaking go player to explain/describe the rule in question.

I find it difficult to believe that what is meant is entirely different from the traditional Japanese way of determining the status of disputed groups at the end of the game. Refinement, perhaps yes. Making clear what might be ambiguous. But not TOTALLY different.

Gérard,

You do not really understand.

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ | a X 2 X O X . |
$$ | X X X O O X X |
$$ | O X O O X X . |
$$ | . O . O O X . |
$$ | O O O O O X . |
$$ | X X X X X X 3 |
$$ | . X . . . 1 Q |
$$ -----------------[/go]

in your example is NOT attached to the double ko.
Therefore, it is dead. It is completely irrelevant for the status of that White could capture Black's stones with a. Just because no group in the upper left is under consideration now.

There are various examples in the J89 text, which explain this principle.

Probably it would help your understanding, if you studied life-and-death problems 19 to 21.
There, the White bent-four-in-the-corner is attached to a Black group that does not have two eyes. The status of White's group depends on the number of liberties of that attached Black group.

Quite the contrary, an isolated bent-four-in-the-corner, which is surrounded by a two-eyed group of the opponent, is ALWAYS dead, no matter the rest of the board.

+ + + + + + + + + + +

"Ad infinitum" in the confirmation phase ALWAYS results in the status "alive" for the group under consideration, if that group had NOT been captured before.

If the group had been captured before, "ad infinitum" ALWAYS results in the status "dead" for the group under consideration, as no new stone can be placed on the board that will remain there forever.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Status assessment under J89 has NOTHING to do with "common sense".

And again, it is COMPLETELY irrelevant what might have happened before the game stopped. Otherwise, there would be NO special ko rule for the status assessment.
However, this special ko rule is unsuitable for achieving the desired purpose in all cases.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

I doubt that you have an understanding of what is "behind the written rule".

Many of your comments are evidence that you haven't even studied the comment and the life-and-death examples extensively.

The authors of the rules tried to declare several types of triple-ko "dead" with the crowbar, but apparently knew that this was against their own rules.
Otherwise, there would have been no need to resort to a construct such as declaring a group dead by "dissolving of the seki", for which there is no equivalent in the legal text.
Should the declared results for the examples 16 to 18 be the intended ones, the authors of the rules should have pored over the wording of Article 7, 2. longer.

Again, study the deciding difference to examples 19 to 21 (bent-four instead of double-ko), which can be solved (i.e. giving the declared result) without any contrary to Article 7, 2.

+ + + + + + + + + + + + + + + +

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . O O O O O O . Q . Q X . X O . O X . |
$$ | O X X X X X X Q Q Q Q X X O O O O X . |
$$ | X X . . . . . X X X Q X O . O X X X . |
$$ | . . . , . . . . X O X X X O O X . . . |
$$ | . . . . . . . . X O X . X O X X . . . |
$$ | . . . . . . . . X O X X O X X . . . . |
$$ | . . . . . . . . X O O O O . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

This position does NOT have the same properties as ...

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . O . Q . Q X . X O . O X . . . . . . |
$$ | O X Q Q Q Q X X O O O O X . . . . . . |
$$ | X X X X X Q X O . O X X X . . . . . . |
$$ | . . . X O X X X O O X . . . . , . . . |
$$ | . . . X O X . X O X X . . . . . . . . |
$$ | . . . X O X X O X X . . . . . . . . . |
$$ | . . . X O O O O . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

... this one, right?

By what reason should it be necessary to enforce that the marked White groups had the same status in both cases? Only because a double-ko is involved?

+ + + + + + + + + + + + + + + +

In examples 19 to 21, the status of the (White) bent-four-in-the-corner depends on the number of liberties of an attached (Black) group.
-- If Black's group has too few liberties, the bent-four is alive.
-- If Black's group has a larger supply of liberties, the bent four is dead.

By what reason should it be necessary to enforce a different behaviour for the status of a double-ko?

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Common sense is not needed. My J2003 interpretation of J1989 treats it correctly:

The big white string is uncapturable due to the infinite alternating sequence B[kkPP]*, where k is ko capture and P is ko-pass. White triangle is neither uncapturable nor capturable-1. Its local-2 is:

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | . X . X O B C |
$$ | X X X O O B B |
$$ | O X O O B B C |
$$ | . O . O O B C |
$$ | O O O O O B C |
$$ | B B B B B B C |
$$ | C B C C C C W |
$$ -----------------[/go]

White triangle is not capturable-2. Therefore, it is dead.

As I wrote earlier you seem to misunderstand what it means to "enable" a new live stone. If you cannot carry out a capture without enabling something (that wasn't originally possible) elsewhere, that is not a valid capture in J89. Spatial locality means nothing - that's why pass-for-ko (with global enabling) was invented for.

The problem with double kos and ko passing is one of the oldest well known defects of the text. But because it would break almost anything it is safe to assume that such perpetual ko passing loop is not allowed - even if the rules authors overlooked the problem.

Other than that, there are several beasts where the ko pass rules change local outcomes and require protecting moves that would not be necessary in normal go. Those are, I think, accepted consequences of J89.

Infinite ko pass cycles have been intended by the J89 authors, see official commentary II.25b. http://www.cs.cmu.edu/%7Ewjh/go/rules/Japanese.html

I meant using a remote double ko (with enabling rule) to prolong analysis. Those moonshine-like problems are the main reason for special rules in confirmation (trying to achieve locality without explicit localization). They clearly aren't allowed - even if the text fails to handle them as intended.

You tell me to study the examples given in the rule but at the same time you say that examples 16 to 18 are mistaken. How can I trust the results given in all these examples?
How can we reach the same understanding? Can we concentrate our attention only on the loop you proposed with the double ko?
In the rule I see four examples with double ko : examples 11, 16, 17, 18. In each of these examples the white group is declared dead by the authors. If I understand correctly your previous posts your declare white alive in the example 16, 17, 18.
Let's try to progress slowly. What is for you the result of example 11?

"Pass-for-ko" is NOT a global issue, but a LOCAL one!

The main challenge of territory rules, like J89, is the iterative process of determining the life-and-death status of groups.

The very first step (which is identical in all the different rules that I know) is to determine whether a group has the status "TWO-EYED life" (which is "unconditionally alive", "uncapturable", etc.).

These "TWO-EYED life" groups enclose and / or seperate areas of the board, which contain groups of still undetermined life-and-death status.

Each of these areas is one "locality", and has to be considered on its own.
NOTHING beyond the border of (a) "TWO-EYED life" group(s) (seen from the inside of any of these areas) affects the determination of life-and-death inside.


The remaining problem is how to handle "ko".
When trying to resolve this problem, you have to be very well aware of potential hidded side-effects.
As we all know, this awareness has been different in the course of history.

+ + + + + + + + + + + + + + + + +

By the way:
I am with you with your understanding of "enable". But this is NOT covered by the legal text.

I hope that we can agree that the primary concerns of the rule were "snap-back" and "nakade".
As I already mentioned before, an addition would have been helpful that the "new stone" had to be established on a board point that had been occupied by the (then captured) group under status consideration earlier.

You will realise that the group under consideration is "unconditionally alive" (i.e. part of a group with two eyes), if ALL previously occupied board points can be occupied again (i.e. a "complete rebirth" of that group).
If only at least one of these pre-occupied points can be occupied again, the group under consideration will be part of a seki.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)