Triple ko again

[John Fairbairn]

A triple ko has just occurred in the Asian Games (Yoshida Mika vs Kim Yun-yeong). It was declared void.

As I understand it, this is thus the umpteenth time the superko rule in the Chinese ruleset has been disregarded, and comments about it seem to indicate strong antipathy to it. There have been several examples in recent times and not following superko has, apparently, not caused any administrative problems.

In fact I am not aware of any instance when the superko has actually been followed. Does anyone know of a case when it has been implemented?

[gaius]

So how did they schedule the replay? I imagine it might mess up their tournament schedule a bit...

[RobertJasiek]

1) Do the Asian Games use the Chinese Rules?

2) If they use the Chinese Rules, then the rules say (1988, but 2002 is said to be similar) in §3.20.3: "In rare situations such as triple ko, quadruple ko, eternal life, and round-robin ko, if neither side will yield, the referee may declare a draw or a replay." This (kind of) referee ko rule is still valid and (as application practice has long suggested) overrides the superko rule, which the Chinese professionals at the 6th International Go Rules Forum confirmed to have been intended for only basic-ko and sending-2-returning-1. Hence application of the referee ko rule would have been entirely correct.

3) As a consequence, one should infer nothing from such correct rules applications about which involved players or referees might or might not prefer pure superko.

4) Rather than overall strong antipathy, there are various indications that players in Japan, Korea, China are split into factions: One favouring exceptional ko rules, one favouring superko (maybe under the name "prohibition of whole board repetition"). E.g., the Chinese professionals at the 6th IGRF said and voted very clearly that they disliked superko; nevertheless, the WMSG 2008 Rules, which were originally written by Chinese professionals around Hua and Chen, then got pure superko (hidden a bit among many words about strategy).

5) Since Chinese Rules applied as original rules by Chinese professionals / referees do not use pure superko, there should also be no reports about superko being applied to long (4+ plays) cycle shapes.

[John Fairbairn]

Thanks, Robert. What you say sounds convincing, but there was a comment in Weiqi Tiandi on a triple ko between He Xin and Zhang Chao on 2008-07-17 which specifically said "in this type of ko" the superko rule was not applied, implying it could or should have been. It referred simply to Clause 20 of the rules. The type of triple ko was the same as the Asian Games one where all the kos were in the same cluster.

If the referee "can" as opposed to "must" intervene, presumably there are criteria to guide him. This implies a decision has to be made in advance so as to be prepared. I imagine this would be in the bailiwick of the organisation running or sponsoring the tournament. The meagre signs so far, taking into account also how referees have handled other kinds of contentious finishes, are that the decision in the case of disputes is to opt for a half-point each in round-robin events or a replay in KO events. In other words, even in a KO they see few impediments to ordering a replay even when the schedule is tight, yet that would surely take a lot longer and be more trouble administratively than applying superko (unless of course we assume, perhaps reasonably, that the superko procedure would, in practice, either would be unpopular or would not actually work - many games are not recorded during play, after all).

Oddly enough, most contentious finishes in recent years seem to have involved Chinese and Korean players. I can't readily recall anything recent under Japanese rules. My guess, however, is that this may have lttle to do with rulesets and more to do with the too short time limits in China and Korea.

[RobertJasiek]

Thank you for the interesting background! Do you have some additional information about Chinese amateurs or their tournaments? What are typical schedules in Chinese KO tournament stages?

[John Fairbairn]

Do you have some additional information about Chinese amateurs or their tournaments? What are typical schedules in Chinese KO tournament stages?

I don't have much information in that regard, but generally prelim games are shorter. However, an interesting point is that, because China is so big, some preliminary rounds are played via the internet. That means games are easily recorded, but it makes refereeing perhaps more difficult. Even stopping an internet clock for a discussion seems to be much more difficult than in a face-to-face game.

[hiyayang]

I think John was referring to the game between two 1p kids in the rank promotion tournament in 2008. In http://sports.sina.com.cn/go/2008-07-19/13233793722.shtml, the chief referee explained the rationale for his decision to declare the game a draw. [On a side note, one of the players was referred to as "Wang Chao", which was probably a typo, as the name tag on the game table appears to contain the word "Zhang" instead of "Wang".]

[hiyayang]

Actually there is a difference between the triple ko situations in the Yoshida-Kim and the He-Zhang games: In the He-Zhang game, black has an eye while white doesn't; in the Yoshida-Kim game (see attached), black has an eye and white would get an eye if she wins the ko at .

In fact, if white won the ko at , she would eliminate the ko at , then the white group is alive with double kos at and , whereas the black group is dead if white can eliminates all ko threats.