Nongshim Cup 221126 Kang Dongyoon(W) vs Tuo Jiaxi(B) (Of course played under the Korean Rule)

Here is the simple explanation.

Are the double-ko at G1 playable during the hypothetical play when confirming the life and death of the large Black unsettled group? Note that Korean rule does not require a pass for the ko recapture during the hypothetical play, but it does restrict that the plays must be made within the "relevant area" (which, of course, has never been formally defined, but explained in examples to a degree).

Actually, the Korean rule list a similar shape as a playable example; thus the rule is applied that way. (A quadruple ko draw requiring a replay) Well, KBA is responsible to keep their words, and that is the right call for today.

Even though I understand there IS some logic for that, I do not like the moonshine life of this type getting a life. Most pros feel that the corner is a locally settled area and better be untouchable during the hypothetical play.

_________________
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

so black cant really capture the white side group. its a ko threat, but as long as white answers with the other ko, white can capture the black group.
if the black group was alive, i'm not sure how to score the kos. if i was the one making the rules, each side gets 1 point for the kos. but by the definition of a point, since they are removable in a sense, i'm not sure.

continue:

_________________
Zhang-hu 章浒
Committed to the restoration Chinese traditional Weiqi
Research on ancient Weiqi rules & Classic (Dunhuang Classic and the Thirteen Chapters Classic)
From Suzhou, Jiangsu Province, China

I will never fail to be amazed at the fact that relevant area hasn't been defined in a ruleset used by professionals

But all professionals "know" what is meant so it doesn't need further clarification!

I suspect that rule-expert professionals don't though. Changing rules is a cultural thing, not just a technical thing.

looking at that position again, i'm not convinced white could actually capture the black unsettled group.
because it would be triple ko. under aga rules, white could capture, but under most other rule sets, it would either be a draw, or the black unsettled group lives.

Black group will eventually die in most rules, including the older Korean rule.

_________________
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

so i agree the two black stones in the corner die giving the following position

but from here black can ko forever.
if white plays q1, black simply plays g1, and white is forced to respond b1.
then black recaptures the ko on q1. white has no move now. white could try to capture the k6 ko, but black could simply take the ko on the seki again. as long as black doesn't fill either of the kos, its draw game.

Wait if passes are not allowed in Japanese rules then in Japanese rules this is only a quadruple Ko if black has more points in black territory that can be played in than white.



Actually in this case professionals didn't know what it meant exactly, they had to consult the rulebook



Yes, you are 100% correct, Japan and Chinese rules try to define a living group as something different to being able to keep it on the board, and instead try to define it in other terms



How on earth is it a locally settled area?

Well.. let's call the small Black group as group 1, White group as group 2, large Black group as group 3.

Group 2 is alive. No one argues against this. What about the others?
If group 3 is alive, group 1 is alive, Right? If group 3 is dead, group 1 is dead. That's why many people say it is an unsettled area.

White only needs to kill group 3 for the victory. If group 1 and 2 lives and group 3 dies, i.e. if White can spare(?) Black by abandoning his right to kill group 1 and make an agreement that it is a settled area, White will gladly accept that. (Of course no rule accepts such a result, unfortunately for him.) The only reason the kos are recyclable under the Korean rule is that group 1's life is unsettled between death and life. (It is the hidden thought why group 1 is included in the "playable" area for the hypothetical play.)

In most logic outside of Go rules, the lack of complete life of group 1 should only benefit White, not giving him a disadvantage. It's like a criminal claiming that "I have five other unsettled charges you must judge, and you are not allowed to hang me until then! (even though other "settled" charges are enough for the punishment.)

_________________
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

By 'playable area' you mean 'relevant area'?

i'm curious to know under aga rules assuming the unsettled group was alive how to score the seki kos.
would both sides get 1 point or no points?
i think you can argue either way.

The AGA Concise Rules of Go say:

Stones in seki are alive. Assuming the unsettled groups are alive, I believe each side gets two points - one point from the eye and one point from an unfilled ko.

AGA rules use situational superko

Those empty points on the board which are entirely surrounded by live stones
of a single color are considered the territory of the player of that color.

but the problem is those stones can be captured in a sense.

I don't think we value how much this kind of puzzles spark a certain kind of interest in Go. Granted, not for everyone (Hell, barely for me!), but... I'm pretty sure it attracts a certain kind of mind, if not yet into the web, and refreshes it, if already captured.

Take care

_________________
玄 之 玄

so a possible resolution to the problem, if black doesn't agree the kos are worth a point, the game is resumed and any stones still on the board after 4 passes are alive.

You mean "consecutive passes" right? You also have to decide what to do if neither side is willing to pass. And whether pass lifts ko-bans. And whether eyes in seki are worth a point. And if not, how to decide which stones are in seki.


If I understand correctly, the result with existing rulesets is:

• Korean: the double-ko seki is in the "relevant area", so the position repeats forever, so no result - the game must be replayed
  
• Japanese: during hypothetical play, pass is required to re-take ko, so the black group dies
  
• AGA, New Zealand (situational superko): eventually black needs to repeat a position, so the black group dies
  
• BGA (natural situational superko): eventually black needs to repeat a position, so the black group dies
  
• Tromp-Taylor (positional superko): eventually black needs to repeat a position, so the black group dies
  
• Chinese: according to sensei.xmp.net, "moonshine repetition is forbidden", so the black group dies? I'm not sure I understand the Chinese rules well enough though.

Personally, I like how superko handles this without requiring any other special considerations. However, applying superko in practice could be quite difficult.

hmm. maybe make a rule if a cycle is repeated 4 times, passes included, any stones involved cannot be captured.
yeah i'd say points in seki count, that makes sense to me.
pass lifts ko ban, but only once.