Triple Ko

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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.

[Diagram]

An example of triple ko

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 [ext] 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.

[ext] Historical triple ko game [1]


Harleqin: I currently have a collection of 10 professional games which ended with no result due to a long cycle (mostly multiple ko):

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 [ext] 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.


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This is a copy of the living page "Triple Ko" at Sensei's Library.
(OC) 2005 the Authors, published under the OpenContent License V1.0.
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