Since we have such big threads on Japanese rules it may be interesting to recall some actual rule disputes from history.

The most famous rule dispute in history is probably one involving the second game of a three game match between Go Seigen and Takagawa Shukaku in 1959. It happened shortly after another rule dispute involving an unfinished ko which apparently prompted the Nihon Kiin to introduce game rules that were later abandoned for the current rules.

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[go]$$ The final position of the game, Go Seigen (White) vs. Takagawa Shukaku (Black)
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X O X O . X O O . . . |
$$ | . O O O O X O X O O O . X . X O O O O |
$$ | O O X X X X O X X O . . . X X O X O X |
$$ | X X X X O O X X X O O . . . . O X O X |
$$ | X . X O . O X X O O O . O O O X X X X |
$$ | . . O . X O X X O O X O O X X X X . . |
$$ | . . . . . X . . X X X O X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

Takagawa claimed that white was missing a reinforcement move while Go claimed he could defend the ko but eventually agreed to 0.5 point loss anyway when the game had been in dispute for months. The issue was that black could start a ko that he has no way to win and he claimed Go had to protect against this. Here one may contemplate that both players disregarded using a pass move as a ko threat.

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[go]$$ White can defend in a ko because black can't win a ko.
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X O X O 2 X O O . . . |
$$ | . O O O O X O X O O O 1 X 8 X O O O O |
$$ | O O X X X X O X X O . 4 . X X O X O X |
$$ | X X X X O O X X X O O 3 5 . 7 O X O X |
$$ | X . X O . O X X O O O 6 O O O X X X X |
$$ | . . O . X O X X O O X O O X X X X . . |
$$ | . . . . . X . . X X X O X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

White could also defend in seki but this would not be fruitful.

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[go]$$ White could defend in seki.
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X O X O 2 X O O . . . |
$$ | . O O O O X O X O O O 1 X 8 X O O O O |
$$ | O O X X X X O X X O . 5 9 X X O X O X |
$$ | X X X X O O X X X O O 3 4 . 7 O X O X |
$$ | X . X O . O X X O O O 6 O O O X X X X |
$$ | . . O . X O X X O O X O O X X X X . . |
$$ | . . . . . X . . X X X O X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

It is interesting to imagine if this happened today. It would appear that if the game ended as it did that white would not have to defend because there is no way for black to capture the white stones, white can use the variation that ends in seki to argue that black can not capture. However, if black had created the ko first before abandoning it then it may appear that white really needs to add a move if one is to follow the current Nihon Kiin rules to the letter.

Click Here To Show Diagram Code

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

The reason black may claim that this is seki is that while his stones are obviously dead he can refer to the current Nihon Kiin rules to claim that the white marked stones are also dead. What he refers to is a rule forbidding white from recapturing the ko without passing once. Article 7.2 of the official Nihon Kiin rules state that during confirmation of life and death that recapturing in a ko is forbidden until the player passes for that particular recapture (paraphrasing here but it is what the English translation says).

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[go]$$B pass for ko at
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X W X O O 1 O O . . . |
$$ | . O O O O X O X W W W X X O X O O O O |
$$ | O O X X X X O X X W . W . X X O X O X |
$$ | X X X X O O X X X W W X X 3 X O X O X |
$$ | X . X O . O X X W W W W W W W X X X X |
$$ | . . O . X O X X W W X W W X X X X . . |
$$ | . . . . . X . . X X X W X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

I find it humorous that white may have to add a stone to avoid a seki that is all dead stones, some of which are in atari and are not ko stones.

Click Here To Show Diagram Code

[go]$$W A seki over there in the center?
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O Z O O X . . . X O O . O O O Z O . |
$$ | . . Z Z O O X . . X O X O O O Z . O . |
$$ | . . Z O O O O X X X X X X O Z Z . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . Z Z . . . |
$$ | . O . O O O . X X X X X O O Z O . . . |
$$ | . O . . . O O O X P X O O . O O . . . |
$$ | . O O O O X O X P P P Z Z P Z O O O O |
$$ | O O X X X X O X X P . P . Z Z O X O X |
$$ | X X X X P P X X X P P Z Z . Z O X O X |
$$ | X . X P . P X X P P P P P P P X X X X |
$$ | . . P . X P X X P P X P P X X X X . . |
$$ | . . . . . X . . X X X P X X . . X . . |
$$ | . . . X . . . . . X X X P P . X . . . |
$$ | . . . X . . . . . P X . X . P P X X . |
$$ | . . . . . . . . . . . X P P X . P P X |
$$ | . . . . . . . . . . . X X P . P . X . |
$$ ---------------------------------------[/go]

White may also offer as a counter argument that while black is able to capture the stones using the rule forbidding recapturing the ko without passing first it is actually in vain because this allows white to play a new stone. This would appear to be referring to the definition of life and death in the rules. The possibility of playing new uncapturable stones is used to handle situations with snapback correctly. The problem here is that the new white stone (at in the next diagram) is almost completely incidental to the whole thing, making it unclear if the argument is valid. If it is valid then the conclusion would have to be that white doesn't have to defend and no possibility of a funny seki. It is only unclear when a new stone qualifies this type of an argument.

Click Here To Show Diagram Code

[go]$$B pass , at
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X O X O O 1 O O . . . |
$$ | . O O O O X O X O O O X X 4 X O O O O |
$$ | O O X X X X O X X O 5 O . X X O X O X |
$$ | X X X X O O X X X O O X X 3 X O X O X |
$$ | X . X O . O X X O O O O O O O X X X X |
$$ | . . O . X O X X O O X O O X X X X . . |
$$ | . . . . . X . . X X X O X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

If someone has some references on how this situation would actually be handled today, whether it is from a book or article on this game, some supplementary to the rules or really anything, it could be interesting to share.

Without being able to cite any reference, I don't think this would be a confirmation or L/D question today. The game simply wouldn't end in a position with any ko potential, regardless of threats. Pass is recognized as ko threat, and even if it wasn't the game can be resumed (and any ko recaptured then).

Simply starting the losing ko sequence would be enough to gain the point for the extra defensive move since W will need to actually win and finish the ko (thereby playing 1 more move in territory).

I had a similar dispute few months ago. That time it was a mannenko which the opponent tried to fight for (with excess threats) even though only I could fill. This would have also meant 1 pt difference, and I think this shows why pass must be a real move (and ko threat), and why resumption must be requestable even 5-10 times if necessary (opp had lots of threats and there were few dame).

The adumbration of the original dispute given above is not really accurate. It was agreed that the Nihon Ki-in rules were clear (fill in the ko). What was not clear was whether these rules applied to Go, as he was not a Nihon Ki-in member. He claimed they did not apply. The full dispute is recounted in my book "Final Summit."

As to the issue mentioned above later in connection with a 10,000-year ko and passes, this has occurred as a problem in pro play. See the game Hayashi-Hashimoto in "The Incident Room" (which covers lots of similar incidents, of course, though in bedtime-reading format rather than the full glare applied in FS).

Click Here To Show Diagram Code

[go]$$B pass for ko at
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X W X O O 1 O O . . . |
$$ | . O O O O X O X W W W X X O X O O O O |
$$ | O O X X X X O X X W . W . X X O X O X |
$$ | X X X X O O X X X W W X X . X O X O X |
$$ | X . X O . O X X W W W W W W W X X X X |
$$ | . . O . X O X X W W X W W X X X X . . |
$$ | . . . . . X . . X X X W X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code

[go]$$B pass for ko at
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X . . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X W X O O X O O . . . |
$$ | . O O O O X O X W W W X X 3 X O O O O |
$$ | O O X X X X O X X W . W . X X O X O X |
$$ | X X X X O O X X X W W X X . X O X O X |
$$ | X . X O . O X X W W W W W W W X X X X |
$$ | . . O . X O X X W W X W W X X X X . . |
$$ | . . . . . X . . X X X W X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

What about this sequence? Black has capture a white stone without enabling a new white stone hasn't she?

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[go]:b5: pass
$$ ---------------------------------------
$$ | . . . O . X . . X X O . O . . . . . . |
$$ | . . O . O X X . X O O O . O . . O . . |
$$ | . O X O O X . . . X O O . O O O X O . |
$$ | . . X X O O X . . X O X O O O X . O . |
$$ | . . X O O O O X X X X X X O X X . . . |
$$ | . O O . O X X X . X O O O O . . O . . |
$$ | . O . . . O O X X . O O . . X X 4 . . |
$$ | . O . O O O . X X X X X O O X O . . . |
$$ | . O . . . O O O X W X O O X O O . . . |
$$ | . O O O O X O X W W W X X X X O O O O |
$$ | O O X X X X O X X W 6 W . X X O X O X |
$$ | X X X X O O X X X W W X X . X O X O X |
$$ | X . X O . O X X W W W W W W W X X X X |
$$ | . . O . X O X X W W X W W X X X X . . |
$$ | . . . . . X . . X X X W X X . . X . . |
$$ | . . . X . . . . . X X X O O . X . . . |
$$ | . . . X . . . . . O X . X . O O X X . |
$$ | . . . . . . . . . . . X O O X . O O X |
$$ | . . . . . . . . . . . X X O . O . X . |
$$ ---------------------------------------[/go]

It is NOT a matter of L&D status confirmation!

Capturing into a single ko-shape allows playing another move in a row locally. But Black needed two here (three in total).

A hanami-ko should be utilised during "play".

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

It would be nice to have a guide, a formula or a theorem to identify if it is a proper end-of-the-game position. I think one can ask beginners to finish the game in a "proper" position but I don't have a good general approach if I was asked to tell someone like Go and Takagawa if they must play more moves. Ideally the rules can be applied to any legal position but determining the result in some positions can be too farfetched to contemplate. For me it is hard to draw a line between "it is not a finished game" and "it is hard to do the status confirmation".




It is a good point that black can capture one white stone and this stone is then dead according to the rules. The rule on removing dead stones at the end of the game is that they must be surrounded by alive stones of the other color only. The consequence of this is that the dead stones in the funny-seki can not be removed at the end of the game, making it akin to seki because the stones remain on the board.

It really seems to be one of those rules-bestiaries.




I don't really know what "adumbrate" means. I was hoping to be able to gloss over the details rather than give a wrong impression.

I see, they decided that it was the rule that ko needed to be protected against. There is a page on sensei's about this but it breaks down into comments, I notice that someone commented something along these lines that Go was up against the rules in use at the NHK and that he eventually agreed with some conditions.

I'd check out your book today, but I can't seem to sort out with the post office where in the world my reissued credit card is




I'd also expect passes to be used as ko threats and black to force the defensive move that way.

I think it is simply when a player has a gainful / score-improving move left it is not a finished position. An open ko or potential ko, even if cannot be won, is not different to a normal teire: eventually need to be protected. Normal teire can be forced by dame fill, protecting/eliminating kos can be forced even after dame fill - by the threat inherent in passes. And forcing teire is a gainful move, even if it is a pass.

Black "pass" => White "pass" => end of "play".

As jann already mentioned, it's a matter of requesting resumption of the game.
It will be White's turn then, and she will have to play a protective move in the centre.

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

Click Here To Show Diagram Code

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

The problem in Go Seigen vs. Takagawa Shukaku game seems similar to the position above.
Black interpretation of the rule is that white must add a move but white interpretation is different. Because here we are with very strong players that means that the rule is unclear somewhere => the two players use in practice two different rules.

In such situation no solution may exist and endless discussions will take place => no result game?

But here we are perhaps lucky.
If the game is resumed then it could follow

Click Here To Show Diagram Code

[go]$$B pass
$$ -----------------------------------
$$ | O . O . X X 2 O 3 O . O . O X . .
$$ | O O O X 4 X X X O O O O O O X . .
$$ | X X X O 1 O O O O X X X X X X . .
$$ | . . X O O O X X X X . . . . . . .
$$ | . . X X X X X . . . . . . . . . .
$$ | . . . . . . . . . . . . . . . . .
$$ | . . . . . . . . . . . . . . . . .[/go]

and now white will add a move.
That means that if you explain to black that white is right (=> white has not to add a move in the initial position) then black can resume the game and white will finally add a move.
Isn't it the same situation in Go Seigen vs. Takagawa Shukaku game ?

BTW there is here another issue with the rule : can the game be resumed after confirmation phase analysis? Several interpretations possible?

It is another example where one side could claim to be able to hold something because of ko threats. The similarity to the shapes proposed in the other threads was one reason I thought to post this.

I find some other things very interesting about the actual dispute:

They stop the game at a point before the ko exists so there is an alternative of defending with seki. Unless there is a resumption it would appear that Go would be right today in the sense that he may only have to concede the defensive move under current NHK rules when the ko has been played on the board.

If they had played the ko shape on the board the position becomes difficult and complicated to explain using the current rules.

I haven't read enough about this dispute, but it always appears to me that historical disputes in Japan tend to enter into a phase that I'd call "consultations" when the game is adjourned and the problem is discussed away from the board. During this period the players may chance or update their stance and some opinions may be expressed. The current rules do not explicitly allow for anything like this, I think because they are meant to be basic rules of play rather than rules governing most aspect of competitive play.

Yes. No.
See https://lifein19x19.com/viewtopic.php?p=267494#p267494

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

Oops, forget my proposed position, it does not work at all

I think the problem boils down to just another instance of a question that turned up earlier, also involving Go Seigen iirc: if a player can leave a ko open, and the other player is unable to win it anyway, is the enclosed empty intersection a point of territory? It would be compatible with both stone counting and area rules.

If I recall correctly, this is also what led the Nihon Kiin to explicitly state that such a ko had to be filled. And that leads to what John said: that this was not a question of how the rules are or should be, but of which rule version was applicable for that match.

_________________
A good system naturally covers all corner cases without further effort.

This is what changed and became (almost) impossible after the invention of passes as real moves (and resumptions).