Life In 19x19

Are you saying that in the sequence

ABCDABCD...

the move D would just be forbidden, regardless of if the position is recreated next time that player wishes to play D?

I can see how D is the correct move to forbid, when it is the the correct move to forbid, but how do you actually tell D from say E? Are we talking about showing the sequence ABCDABCD... and then backtracking to ABC and banning D? Could D then ever be played after that?

For example is ABCEFD legal? I guess not.

This has an Ing rule vibe. This is effectively same as the disturbing ko rule, right? or wrong?

kvasir wrote:Are you saying that in the sequence

ABCDABCD...

the move D would just be forbidden, regardless of if the position is recreated next time that player wishes to play D?

I can see how D is the correct move to forbid, when it is the the correct move to forbid, but how do you actually tell D from say E? Are we talking about showing the sequence ABCDABCD... and then backtracking to ABC and banning D? Could D then ever be played after that?

It's a bit difficult to transpose the results from the "two-eye-formation" world into the "uncapturable" world, as both worlds are divided by a one-move difference, which has a big decisive effect.

In the "two-eye-formation" world, it is possible to ban the last move of EVERY cycle.
With the cycle, the player moving last will be unable to create a "two-eye-formation", due to its infinite repetition.
Without move "D" in your example, it is likely that something of this player will "die" in the confirmation sequence. Which leads to the same result of being unable to create a "two-eye-formation".

You will easily see the difference to the "uncapturable" world.
-- In the "two-eye-formation" world, "chôsei" has the same effect as "killing" something (elsewhere).
-- In the "uncapturable" world, "chôsei" has the same effect as "living" with something (elsewhere).

For example is ABCEFD legal? I guess not.

In the examples analysed at that time, banning referred to the repetition of the UNinterrupted course of a cycle (i.e. "D" must not be played after the next appearance of "A", "B", "C" in order).
Thus, it would be allowed to play "D" later (here after "E", "F").
(But it did not appear something like a one-time "ko-threat" "E" that had to be answered (with "F") in-between, at that time.)

However, if just another cycle was created, "D" would be banned again. Just a bit later.

This has an Ing rule vibe. This is effectively same as the disturbing ko rule, right? or wrong?

If I understand correctly what Sensei's Library says about it (I had nothing to do with "fighting" / "disturbing" ko before), I would say "Yes".
If the last move of a cycle is a "pass", this cycle belongs to a position, where both sides capture different stones. In J89, it has the effect of preventing the L&D status confirmation from ending. J89's authors should have simply (and explicitly) forbidden the endless repetition of cycles, where both sides capture a DIFFERENT number of stones per pass (despite the fact that "captives" do not count during status confirmation).

I struggle to understand everything you have said. This may just be my confusion but it is still unclear to me how you pick the move to ban.

I showed this sequence.

Click Here To Show Diagram Code

[go]$$W :w3: pass-for-ko :b4: pass-for-ko
$$ -----------------------
$$ | X X X . O X 1 X O . O X . .
$$ | . O O O O X X O O O O X .
$$ | O O X X O X O 2 O X X X
$$ | . O X O X X X O O X .
$$ | O X X O X . X O X X .
$$ | X X X O X X O X X . .
$$ | . . X O O O O O . . .
$$ | . . X X . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

Click Here To Show Diagram Code

[go]$$W :w7: pass-for-ko :b8: pass-for-ko
$$ -----------------------
$$ | X X X . O X O 6 O . O X . .
$$ | . O O O O X X O O O O X .
$$ | O O X X O X 5 . O X X X
$$ | . O X O X X X O O X .
$$ | O X X O X . X O X X .
$$ | X X X O X X O X X . .
$$ | . . X O O O O O . . .
$$ | . . X X . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

You seemed to say is the last move of the cycle. I am pretty sure that repeats a board position WITHOUT forming a cycle of moves because a move like has never been played.

The cycle of moves is to
The first repeated position is after (I am not mentioning passes because they are either ignored or we treat pass-ko bans as part of the position)

Basically, it is possible to repeat a board positions more frequently than you loop through the cycle.


For example what seems to work with my understanding of cycles and both example 17 and 23 is to ban the first board move in the second repetition of the loop (or second cycle of the loop, if I adopt your definitions), but I have no particular reason to think this works in general. Possibly one could count the number of board moves in the cycle instead and declare a ban on the player that has more board moves, but same, I have no particular reason that this would work in general.

The disturbing ko rule as stated by Ing really leaves it to intuition to decide who is the disturber and therefore who must break the loop. But I fear it may not be so simple to decide which side to punish.

kvasir wrote:I struggle to understand everything you have said. This may just be my confusion but it is still unclear to me how you pick the move to ban.

In the world of "two-eye-formations", there is NO "pass-for-ko".

Click Here To Show Diagram Code

[go]$$W :w3: pass
$$ -----------------------
$$ | X X X . O X 1 X O . O X . .
$$ | . O O O O X X O O O O X .
$$ | O O X X O X O 2 O X X X
$$ | . O X O X X X O O X .
$$ | O X X O X . X O X X .
$$ | X X X O X X O X X . .
$$ | . . X O O O O O . . .
$$ | . . X X . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

Click Here To Show Diagram Code

[go]$$W :b6: pass
$$ -----------------------
$$ | X X X . O X O 4 O . O X . .
$$ | . O O O O X X O O O O X .
$$ | O O X X O X 5 X O X X X
$$ | . O X O X X X O O X .
$$ | O X X O X . X O X X .
$$ | X X X O X X O X X . .
$$ | . . X O O O O O . . .
$$ | . . X X . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

is the last genuine move of the cycle, thus will be banned. Thereafter, Black will end the discussion by capturing White's group to the right.

-- The initiator of this double-ko cycle (which is NOT an enforced one; Black could continue in the upper left corner, instead) will lose his double-ko group for sure.
-- Thus, starting this double-ko cycle is discouraged.
-- Thus, there is NO double-ko in L&D status assessment.
-- This is the intended result.

------------------------------

The original J89 "pass-for-ko" ruling (for the "uncapturable" world) was NOT appropriate to kill any double-ko cycle (an 8-move one there).

Click Here To Show Diagram Code

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

Has white to add a move?

Gérard TAILLE wrote:

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

Has white to add a move?

I have stated my opinion elsewhere that the pass-ko ban remains there as long as the hot stones is on the board.

I think you can also consider this shape when white is clearly dead because of pass-ko.

Click Here To Show Diagram Code

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

Rather than ask if the ko is the same, should we ask if it is really the intention in j89 to let one side win a ko that would require a ko threat? Both of these position we have situation that white would win the ko if neither side had a ko threat, it appears odd to me that we would decide against white if there is not supposed to be ko fights in status confirmation.

kvasir wrote:

Gérard TAILLE wrote:

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

Has white to add a move?

I have stated my opinion elsewhere that the pass-ko ban remains there as long as the hot stones is on the board.

I think you can also consider this shape when white is clearly dead because of pass-ko.

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X . O .
$$ | O O O O O X X X O O .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

Rather than ask if the ko is the same, should we ask if it is really the intention in j89 to let one side win a ko that would require a ko threat? Both of these position we have situation that white would win the ko if neither side had a ko threat, it appears odd to me that we would decide against white if there is not supposed to be ko fights in status confirmation.

I had the same understanding Kvasir but now I have a doubt:

Click Here To Show Diagram Code

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

"a" was a ko earlier and "a" may be a ko in the future but in the position above "a" is no more a ko. How a pass-for-unexistent-ko can make sense?

Gérard TAILLE wrote:I had the same understanding Kvasir but now I have a doubt:

I think we may just be at the end of the line for pass-ko.

1. It doesn't seem to give the results we want.
2. It raises questions that wouldn't otherwise need to be answered precisely.
3. It is fairly tricky to actually use this rule.

Gérard TAILLE wrote:

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

This is what I referred to here and here. This seems significant well beyond J89, because a complete ruleset will likely need (for moonshine kos) to EITHER rely on "wholeboard position" (like superko) or include rules referring to "the same ko". OC, both have huge weaknesses.

jann wrote:

Gérard TAILLE wrote:

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

This is what I referred to here and here. This seems significant well beyond J89, because a complete ruleset will likely need (for moonshine kos) to EITHER rely on "wholeboard position" (like superko) or include rules referring to "the same ko". OC, both have huge weaknesses.

It does not make sense to want to heal errors during "play" in the subsequent L&D analysis.

Click Here To Show Diagram Code

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

White would connect with , wouldn't she?

After some contemplation I think this example is suspect because of blacks outside liberty.

Click Here To Show Diagram Code

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

The rules include the following commentary.

Commentary on Article 9, End of the Game, Clause 2
1. Confirmation of the life and death of stones and territory requires that the players fill the dame and add any necessary stones inside their territory, in accordance with Article 8.
2. If the players agree, they may fill the dame and add other necessary stones after stopping the game, in which case these are not moves as defined by the rules, and need not be played according to the rules.

We have actually discussed this before, how the commentary says that dame is required to be filled and then shows examples that apparently state it is too late to fill dame. At any rate, examples that dispute the life and death but leave an outside dame are suspect.

You could create an example were the outside white group may be dead but you may find that it is then black that is failing to fight the ko.

kvasir wrote:After some contemplation I think this example is suspect because of blacks outside liberty.

$$W
$$ -----------------------
$$ | . X X O O . O X C O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

The rules include the following commentary.

Commentary on Article 9, End of the Game, Clause 2
1. Confirmation of the life and death of stones and territory requires that the players fill the dame and add any necessary stones inside their territory, in accordance with Article 8.
2. If the players agree, they may fill the dame and add other necessary stones after stopping the game, in which case these are not moves as defined by the rules, and need not be played according to the rules.

We have actually discussed this before, how the commentary says that dame is required to be filled and then shows examples that apparently state it is too late to fill dame. At any rate, examples that dispute the life and death but leave an outside dame are suspect.

You could create an example were the outside white group may be dead but you may find that it is then black that is failing to fight the ko.

I do not see your point Kvasir.
In NORMAL PLAY and black to play then Black stones are dead because white has the advantage in the following ko fight. Now I just ask if they are also dead in CONFIRMATION PHASE which is less obvious.

kvasir wrote:At any rate, examples that dispute the life and death but leave an outside dame are suspect.

What is dame and what is a point of territory next to a dead string depends on status. During a dispute you cannot tell this in advance.

jann wrote:

Gérard TAILLE wrote:

$$W
$$ -----------------------
$$ | . X X O O . O X . O .
$$ | . X O O . O X X O O .
$$ | O O O O O X X X O . .
$$ | X X X X X X O O O . .
$$ | O O O O O O O . . . .
$$ | . . . . . . . . . . .
$$ | . . . . . . . . . . .

Click Here To Show Diagram Code

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

This is what I referred to here and here. This seems significant well beyond J89, because a complete ruleset will likely need (for moonshine kos) to EITHER rely on "wholeboard position" (like superko) or include rules referring to "the same ko". OC, both have huge weaknesses.

Yes Jann I noted your interesting comment in https://www.lifein19x19.com/viewtopic.p ... 46#p267746

Click Here To Show Diagram Code

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

After the exchange it is true that the strings adjacent to the ko have changed but according to article 6 the ko itself has not disappeared. For that reason I searched for a another (more?) convincing situation.
I do not know if the original text in japanese can help but seeing the english text it is not clear what happen for pass-for-ko request when a ko disappears and reappears later : is it a new ko at the same place or is it the same ko?

I don't think this was ever defined anywhere, so you are on your own.

"A ko capture is IN THE SAME KO as another ko capture if it is in the same ko mouth formed by the same strings."
(change strings to stones for the other, less strict way - the third, most liberal way won't even require same stones)

I'm still reluctant to actually suggest such definition (or any other definition for this), but some reasoning can be found, even theoretically. What happens if you judge NOT same ko? You get normal ko behavior, which is almost never wrong. So the strictest definition may be the most safe. OC with J89 you also need to worry about Japanese compatibility... This whole thing is a mess, and the mere fact that this is a question is a weakness of these ko-related special rules.