There was an interesting game in a Women's professional league game. (Youngjoo Lee (W) vs Minjin Lee (B))

It is in the third figure of the following article.
http://baduk.hangame.com/news.nhn?gseq=66073&m=view&page=1&searchfield=&leagueseq=0&searchtext=

I've yet to see the on-air commentary, so I do not know how the referee explained it.
Anyway, the conclusion seems to be correct in the current Korean ruleset. Also, the conclusion is the same in the current Japanese ruleset. In both cases, White can find a hypothetical play to capture all Black stones.

White does not need to make a further play at the upper left corner, and that ended the game with W + 0.5 win.

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5

Thanks for this,

I do not read Korean, so I don't know what happened. Several years ago I saw a translation of the Korean rules into English, but the rules have, I believe, changed since then.

What was the basis of the dispute? A claim that White needed to capture the Black stones in the top left corner? At the cost of 1 pt. of territory? Why?

Such a capture is not necessary under the Nihon Kiin rules. I don't think that it is necessary under Ing, Chinese, or AGA rules, either. Is that right?

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Is it possible that these situations occur rarely enough, that even pros are taken by surprise by this rule? When one estimates the score with many more moves to go, I imagine one assumes all capturing moves have to be played, since that is the case in 99% of the games (just a wild guess), then that assumption is typically carried over to the end of the game, in the counting stage, by most players (?).

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Sorin - 361points.com

First, the dispute is about unsettled ko at the upper left corner. If Black has enough ko threats, she can keep playing to capture all the upper White group, but she now ran out of ko threats. As usual, Black's claim can be "The ko is unsettled yet, and White must make one more move to remove the ko" (and lose one point).

It may be a little bit confusing at a first glance, but it is basically a one move approach ko. You surely know all the rule disputes Nihon Kiin experienced on this subject. The current Korean rule is not the same as the Japanese rule, but the conclusion on this shape is the same: "If the game ends at this shape, White does not need to make another play."

Under most (if not all) area scoring rules, White will gladly play more stones to remove the ko which does not cost her any points after filling in all the shared empty points.

Regarding the status of the Korean rule, the most up to date ruleset is 2016 version, but it is not so different from the Asian Game 2013 rules posted at https://senseis.xmp.net/?KoreanRules.

I am preparing English translation of my book "Understanding the rules of Baduk" which of course includes the current Korean ruleset. I should have finished the translation a year ago, but it goes on forever. I will post the Korean ruleset part of the book in the next message, and add some more explanation.

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5

I am attaching an sgf file with the top left corner. It is an approach ko, albeit a humungous one. I don't think that approach kos are all that rare. It is true that not many people understand the theory behind approach kos. (Actually, there is no single theory, but every one that I know of deems this position to be final, given Black's lack of ko threats.) The game record should be quite interesting.

The Korean rules that I saw years ago had intricate end of game rules that I did not understand. I don't know about the current rules.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Only an absolutely accurate translation of the Korean 2016 Rules might enable our judgement of correct rules application or assessement that rules ambiguity prevents it. Similarity to the Asian Games 2013 Rules or rough relation to Japanese rulesets are insufficient.

The official rule is no better than the 2013 Asian Game rule, so it will certainly disappoint you. I had trouble reducing it within 2MB. I will post the ruleset in the next post.

For those who want the full sequence of the game, I attached the sgf file. The half-point ko at the left side was unnecessary. Black probably failed to count the territory correctly, and walked into the trouble by playing at 331.

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5

The current Korean ruleset is attached in this message as a pdf file. The introduction in the first page is still messy, and from the second page, I made a direct translation of the Korean text into English. (It is part of the book I published in 2017, and I am translating it slowly now.)

Not surprisingly, it is ambiguously written, and it is practically impossible to understand how life and death dispute should be settled just by reading this short text. Here is a somewhat sarcastic Q&A.

Q: This should be an abbreviated version. Where is the full text?
A: This IS the full text.

Q: Is there.. a kind of official commentary?
A: No.

Q: Are there more examples explaining the application of the rule?
A: No. This is all they have.

Fortunately, I made a few visits to the authors of the old and current Korean ruleset and asked them many questions to understand their true intention. Well, you can guess how the conversation really went. It is like this: (Q: So.. what happens when both players' stones are identified as dead? Does this rule accept anti-seki? A: Uhh.. what are you talking about?)

Anyway, from that experience, here is the best interpretation I can make from their responses.

1. It works like the Japanese rule. i.e. make a hypothetical play to settle disputes.

2. There are two clear differences from the Japanese rule. The first one is, "For the hypothetical play, do not play anywhere outside the region of dispute." Is the region of dispute well-defined? Of course not, but R. Jasiek's local-1,2,3 may give you a decent idea which area should be included and which area should not. (I mean, I am saying so, not they are saying so.)

3. The second difference is that you do not need to make a pass to recapture a ko during the hypothetical play. The result? Well, a combined moonshine life can make a draw or local seki, instead of unconditional death.

There are still ambiguities that they fail to answer (of course, anti-seki is one of them), but at least for the game we are discussing, it should be enough to conclude that White's reinforcement is unnecessary. It is another question if the referee clearly knew all of these. He may have just said "Well.. it is a one move approach ko, and in this case the ruling is ....".

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5

Is it just me or do almost all of these rules disputes boil down to: "this would not have happened with area scoring"?

jaeup, very many thanks for your contributions and informations about the Korean Rules! I will read the English texts.

It's not just you.

I have been referee for a french tournament (with area scoring) but I would hate to be the referee for a tournament using japanese or korean rules.

I don't know what would be the worst case : not knowing what to do with the above situation under korean rules, or having to explain to the players that recapturing a ko just after having made a proper ko threat is illegal during the confirmation of life and death under japanese rules.

Oh, and the problem is not territory scoring. The problem is the unwritten tradition that considers life and death to be determined with both white to play and black to play from any position, and with all ko bans lifted.

If the tradition was just to consider what could be captured if the game would have went on, it would be completely different.
But that would imply that you have one point of territory inside the last ko if you avoid filling it and if your opponent can't win the ko. No one is ready to accept that.

Now, I watched the broadcast of the game and a few other comments on this game.

They are all saying "White does not need to reinforce because it is a one move approach ko". Well, the conclusion is correct, but do they really know why? I feel like seeing a student who solves a math problem using a given formula, but does not know why the formula is valid.

Both players made many mistakes at the endgame, and this was Black's last chance. Black A can create a direct ko. Black can win by 0.5 regardless of the ko threats. (White B? Black can play at C.)

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5

Thank you very much for the translation and discussion of the current Korean rules.



Indeed. I would say that it is worse than ambiguous, it is not well defined. Still, if it suits the Korea Baduk Association, I am not one to complain about that.



This is a problem for both referees and players, however.



Capturable is not defined, however. My guess is that alternating play is assumed, and also that stones that would be captured in a fight that belong to the winner of the fight are not considered capturable.



The Japanese pass for ko rule is, IMHO, one of the abominations of the Japanese 1989 rules.



And the anti-seki is an even worse abomination. The J89 rules are too clever by half. Good for the Koreans for not following suit.

Another good feature, IMO, is that a pass is not a move, and that players are not supposed to pass until necessary, filling dame during play. No pass baduk and territory scoring go together. It is reasonable to stop play in no pass baduk when the next play would entail a loss, such as filling a point of territory.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

You don't have L&D disputes with area scoring since there is no L&D, otoh it has its own potential problems and disputes.

A pass is enough to lift the ko ban (and play can be resumed if necessary). It's more problematic with superko (and a problem source for area scoring), but easy and straightforward with normal ko.

Well, players knew instinctively about double ko seki for centuries if not millenia, but it was only in 1998 that I discovered a theory that could prove it. As for this being a final position in an approach ko, Professor Berlekamp proved that with komaster theory around 30 years ago. It is too bad that his theory has not been adopted (yet) by baduk professionals.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Well, territory scoring has a natural stopping point when there may be ko fights in later play. How to deal with that is a real question.



Well, that is one viewpoint (and one I share) but it is not the only traditional viewpoint.



Well, both Honinbo Shusai and Go Seigen accepted that.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Apart from the usual specific mistakes of the Korean 2016 Rules, they show an unprofessional attitude. From ruleset to ruleset, they substitute some beginner mistakes by other beginner mistakes. They hope to solve rules by trial and error but this does not work as long as well known mistakes recur. Korean professional players write rules like a beginner plays the game.

Hopefully, they learn from your book, after which they can no longer pretend a language barrier.

The videos are on BadukTV's youtube channel. First one shows the prelude -- Black plays a ko threat, but white ignores it. The leads to the difficult fight in the upper left corner.
https://www.youtube.com/watch?v=O0LlIyE0RuQ

Here you can see the dispute from 2:30 to 4:30. BTW the referee who shows up is Kim Hyunghwan 8p (김형환), who will be attending the US Go Congress.
https://www.youtube.com/watch?v=OMyGhjArMIY

Also at :45 white plays atari on 4 stones instead of taking the ko (the commentator was expecting white to take the ko). It takes him 10 seconds to realize and start explaining that white will still win because white is ko master and won't have to fill the ko.

Another fun point: the players have so many prisoners that the final score is black 2, white -4. After 6.5 komi, white wins by 0.5.

Language is not the biggest problem, I agree, but it is at least a big problem. When I asked KBA if they have Korean translation of the Japanese and Chinese rule, they simply said no. Well.. I decided to make my own translation, but I do not think they really read what I gave them.

Foreign players frequently play tournament under Korean rule, and KBA never distributes them the Korean rule. (They do not even have Japanese/Chinese/English version of the Korean rule.) To be fair, Korean players visiting Japan or China does not get a piece of paper explaining the ruleset they must play with.

I assume they learn other rules by word of mouth, well... in 21st century.

_________________
Jaeup Kim
Professor in Physics, Ulsan National Institute of Science and Technology, Korea
Author of the Book "Understanding the Rules of Baduk", available at https://home.unist.ac.kr/professor/jukim/bbs/board.php?bo_table=notice&wr_id=5