Triple Ko in Korea

[Ferran]

Lee Changho and Shin Jinseo managed to get into a 3x Ko today. By the tournament rules, Myungjin, the replantejar used the remaining time. That must be quite a whiplash.

Take care

[jlt]

Isn't it Shin Jinseo (instead of Minjun)?

[Ferran]

Isn't it Shin Jinseo (instead of Minjun)?

Yes, sorry. My brain skipped a track. Edited.

Take care

[kvasir]

How often has this happened to Lee Changho?

[John Fairbairn]

How often has this happened to Lee Changho?

It has not happened before to Yi Ch'ang-ho in any of his 2,078 games in the GoGoD database.

In GoGoD there are 47 triple ko games. 37 ended as void (either replayed or counted as a tie). Others were played on except for one where a player made an illegal, move within the triple ko and so lost.

There are also a few quadruple and quintuple ko games.

On this basis the rarity of a triple ko is 47/126,000 or 1 in every 2,680 games, with a couple of caveats. One is that triple kos can occur in variations that are not actually played. The other is that I tend to collect interesting games over boring games, and triple kos count as "interesting". We can perhaps assume these caveats cancel each other out.

Also on that basis, with around 5,000 pro games being played each year at present, we should expect two visible triple kos a year on average. There were indeed two last year, with one being argued over as a possible quintuple ko.

The earliest triple ko we know of with actual moves is 1724 (i.e. well after the possibly mythical Sansa-Rigen case, but triple ko positions (given in problem collections) were known in China long before that. China also had the famous Windlass Ko game (two double kos) around 1735.

[Ferran]

If I find it, I'll post the whisplash Mickey Mouse game. Take care

[kvasir]

It has not happened before to Yi Ch'ang-ho in any of his 2,078 games in the GoGoD database.

There should at least be the exhibition game with Chang Hao that was played at the Great Wall or some similar fortification. Maybe it was a quadruple ko, maybe it needn't have been a no result if one of the players had found a better move during the game? I think there might have been a giant Go board involved.

I can't remember any other specific case, but I thought there could be more.

[John Fairbairn]

That game was in 2005 on the largest open-air go board in the world (so conceivably the result was contrived for the vast public) to showcase the reopening of the Southern Great Wall.

It was counted as a void quadruple ko after 369 moves. Yi could have won by giving up one ko but was under sudden-death time pressure.

[kvasir]

Ryu Shikun, 4 times Tengen and Oza, was streaming during the game. It is in Japanese and a few hours long but it might be of interest to some. There are machine translated subtitles available and the playback speed can be increased (my favorite). His fish tank is pretty cool and it looks like he streams regularly on youtube in Japanese and Korean.

[Ferran]

The SGF at Go to Everyone's site seems to be replay.

Enjoy

[botija]

IIRC Lee Sedol had an unusual high rate of void games by triple and quadruple kos. It was discussed if it was a consequence of his fighting style or a strategy he displayed when things didn't go well for him.
(All of this subject to verification)

[John Fairbairn]

I have three -ple kos by him, which is obviously above average. One was a triple, one was a quadruple and the other was subject to debate as to whether it was triple or quadruple.