Triple Ko
In a Triple Ko, there are three Kos on the board. all in play at the same time. Often they are part of the same configuration, as in this example.
Say you have the kos a, b and c. You take a, your opponent takes b, you take c. Your opponent retakes a, you retake b and he retakes c. With the simple ko rule, you could now retake a again, and the cycle would go on for ever.
Of course, this is undesirable. Traditionally, a triple ko meant no result, and was considered unlucky.
In October 1998, the fourth game of the Meijin title match
ended without result when neither O Rissei nor Cho Chikun would yield in a triple ko.
Several modern rulesets handle it with a superko rule.
See the /Discussion page for more.
Harleqin: I currently have a collection of 10 professional games which ended with no result due to a long cycle (mostly multiple ko):
- 1724-04-27, Inoue Shunseki - Nagano Kaizan? [2]
- 1970-09-16, Fukui Masaaki - Cho Chikun
- 1975-07-10, Cho Chikun - Kato Masao
- 1980-05-25, Matsuoka Akira - Yanagawa Hiromasa?
- 1984-05-24, Qjan Yuping? - Katoka Satoshi?
- 1985-05-28, Liu Xiaoguang - Awaji Shuzo
- 1989-01-28, Kono Mitsuki - Kurotaki Masanori
- 1993-09-02, Komatsu Hideki - Rin Kaiho
- 1998-10-14, O Rissei - Cho Chikun
- 2002-03-15, Qiu Jun - Yu Bin
Steve: Another game with a long ko cycle was in the 2005 Southern Great Wall Cup, Chang Hao - Yi Ch'ang-ho
Bill: It's a quadruple ko, a combination of two direct kos plus a double ko death.
There is also an amateur game from the 2003 Frankfurt Go Tournament:
- 2003-05-18, Simon Kober 16 kyu - Bjoern Wenzlaff 18 kyu (quadruple ko, a photo is on the cover of
DGoZ 3/2003)
[1], [2] These seem to be the same, though they are attributed to different players. I don't know which is correct.
John F. Re "the" historical game - what are you referring to? The linked site clearly says 1724 then the lunar date.
Harleqin: Sorry, I made the footnote clearer now.
John F. I'm still none the wiser - the players are the same.
You obviously have the GoGoD version since you use our dating, but the year's the same either way.
Harleqin: I think I have most of these games from Jan van Rongen's "Friday Night Files" site and from gobase. I use the dating I like, in order to sort my records chronologically.
I say "the" because it's not the only historical game - there is also Sekiyama-Ito. We can't claim to be complete, but as a benchmark you may wish to note that GoGoD has 12 triple ko games, 10 quad ko and 2 chosei (not quite all on the CD yet). We have a note of a quintuple ko in an amateur game in Japan, but haven't seen it yet. Can anyone construct such a monstrosity?
Harleqin: Is that a rhetoric question? It seems rather trivial. Forcing one in a real game is, of course, another thing ;).
Mef: I assume he means a quintuple ko where none can be filled without losing. John F. Yes
Chris Hayashida: I don't know about the quintuple ko, but when I hear of a historical game with a triple ko, I think of the one played by Sansa and Riken the day before Nobunaga was betrayed. It was also referenced in the Hikaru no Go manga. I suspect this is the "historical game" that he is referring to. I don't know what the date is of that game, nor do I know if the web site is correct.