Interesting double/potential triple ko(/seki ?)!

An interesting position came up in a game – it’s a double ko with a group with 1 eye vs no eyes + an unresolved third outside ko for liberties…, with the potential to have turned into a triple ko if one or both players continued playing after the first pass. (I think)

(I’m not 100% certain whether white can actually capture the big group, as black can perhaps use the double ko for infinite ko threats/turn it into a triple ko if white tries ?)

We both ended up passing in the game, but I feel the position was very fascinating and wasn’t 100% sure how to judge it.

Is it dead, alive in a strange infinite ko ? Triple ko ?

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I see no way to stop triple ko cycle.

seki is when you lose if you do something
here you lose if you stop doing something
looks incorrect to give victory to anyone

You are playing under Japanese rules, which means that Black is dead and White wins.

This is because, in playing out captures to determine the life and death status, to recapture a particular ko, you must first make a “pass for that ko”, i.e. point to the ko and dedicate a pass specifically to it. Black can never recapture at A5, since after his pass, White can already capture Black who is in atari.

See here under “Life-and-Death Example 8”.

One point that I myself do not understand about Japanese rules is that there is no superko except No result by mutual agreement. If Black does not want to go to scoring, because he would lose, can’t he play on forever without restrictions on capture? I don’t think the rules deal with this situation.

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I think black will run out of legal moves eventually. If we look above at when black passes in the game, black can’t recapture H9 because of the ko rule, doesn’t want to fill either of the other two kos, but then there’s only a finite number of non passing moves they can make in whites territory.

If black is giving away prisoners or filling their own territory to avoid scoring it might be the case that white can even give up the triple ko group after enough additional points are given.

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Its not Chinese rules - its not superko, black can continue forever, I tried. No one accumulates prisoners faster than opponent here, you can’t stop protecting and still win later.

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Thanks! It seems black needs a second double ko position for endless repetition. ^^

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I’m not sure what you mean, white can keep passing in the double ko, and that’s no gain for anyone, but black will have to keep adding stones to whites territory while white is passing to avoid scoring and so white gains prisoners.

I made an example variation in the game.

As in Black will have to place dead stones in whites area, white passes, then black takes double ko, white takes, and black has to give another prisoner etc. then eventually white can give up the group at the top if needed.

if after black’s pass, white passes too, black has right to return to game and continue. Counting begins only if both players wish to count.

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Yeah but this is kind of intentional stalling. Like equally you can just disagree on the score count or the status of a group and then you might as well just get a referee to help.

I suppose both can be seen as flaws in the rules.

And if white do 2 moves in a row, black still can save the group

???

If you want the game to continue forever like with a triple ko kind of repetition.

If you pass pass, pause the clock and then want to resume because you don’t agree the black group is dead, then we either call a referee that tells you the black group is dead or we play on with the special ko rules and then black gets captured.

I believe white can demonstrate black is dead by playing first, but black can’t demonstrate white is dead by playing first, because of the double ko.

I heard of some special different rules inside hypothetical play in Japanese rules after game “ends”. But what if black passed not in order to end game? If white passes, rules says that reason of black’s pass have to be ignored?

https://www.cs.cmu.edu/~wjh/go/rules/Japanese.html

Under article 9 the rules say “When a player passes his move and his opponent passes in succession, the game stops”. It doesn’t make an exception for any subset of passes that where made with some specific intention.

3. If a player requests resumption of a stopped game, his opponent must oblige and has the right to play first.

looks like resume of full version of game, without special ko rules

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Yes, you can resume the game, but that isn’t affected by the reason that black passes. Like, black could pass because they wants the game to end, and then once the other player passes black might change their mind and want to resume.

I think though providing for what happens if the person is just refusing to end the game, probably isn’t in the spirit of a lot of rulesets.

It does make sense to have some decisions on what to do in certain shapes, especially when playing it out costs points like in Japanese rules.

I don’t think it needs a rule for what happens if someone passes, you go to scoring, resume only for them to pass again and so on.

It’s kind of like having a rule for when someone takes your queen in chess without capturing it and refuses to give it back.

You just stop playing with that person :slight_smile: Or you call a referee in a tournament etc.

so,

black can’t play G9, so black pass, white pass
black requests resume of game, white requests playing first

black protects
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its forever cycle, black don’t even have to pass again to protect himself.


if white don’t wish to play first or requests playing first but playing pass instead of stone, then can black play G9?
If yes, its still forever cycle. If no, its seki.

I’m not sure resuming is supposed to lift ko bans, even if it does on OGS say.

I think passing is supposed to signal an end to the game, resuming is probably supposed to fix some things that might have been forgotten like playing some extra missed dame. It’s not supposed to be some exploit to try continue the game forever.

There probably is an element of “spirit of the rules” in some interpretations. I remember asking something before about having a double ko on the board and how passing for kos are supposed to work but it’s a bit unclear.

This case is just ruled dead though, eye vs no eye, and I think it’s semi clear how one side captures the other with some version of passing to recapture kos.