According to Bill Spight or Robert Jasiek approaches double sente positions seem to not exist. In the context of their method it must be true but as a Go player I have not the same feeling.
Let's take the following example:
Assuming an ambiant temperature greater than t = 1 my analysis is the following: to avoid the opponent to play hane, both players must play sagari in sente BEFORE decreasing the ambiant temperature under t = 1. The position being symetrical this position is for me sente for both players; one of the player (it does not matter which one!) will necessarily play sagari in sente to avoid playing in the environment and decreasing the temperature under t = 1.
Can a double sente position exist?
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Gérard TAILLE
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RobertJasiek
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Gérard TAILLE
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Re: Can a double sente position exist?
How do you call this position as a local position?RobertJasiek wrote:Local double sente vs. global double sente.
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RobertJasiek
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Re: Can a double sente position exist?
For this class of positions with tentative sente and gote options for both players, I have not developed a local nomenclature.
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Gérard TAILLE
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Re: Can a double sente position exist?
OK Robert.RobertJasiek wrote:For this class of positions with tentative sente and gote options for both players, I have not developed a local nomenclature.
I said I considered this position double sente. That means that my analyse tells the go players that any of the two players can choose the sente option and tells also that one of the two players (it does not matter which one) must eventually play this sente move.
Robert, what your method tells the go players?
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RobertJasiek
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Re: Can a double sente position exist?
As I have explained before, my theory is not developed for a local endgame with both players' tentative gote and sente options but some option can be temporarily ignored for indicative study of tentative move values. I have also suggested many times to consider global double sente for informal theory fot go players, and this is more suitable for your example.
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xela
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Re: Can a double sente position exist?
I don't think there's a standard term yet. Personally I call it: "This will become double sente when the game temperature drops below <number>". Who gets to play it as sente depends on who plays the move elsewhere which causes the temperature to drop below the threshold.Gérard TAILLE wrote:How do you call this position as a local position?
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John Fairbairn
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Re: Can a double sente position exist?
Gerard: It sounds like you are seeking something that is useful in practical terms while at the same time seeking to find the far end of a fart. The two things are incompatible.
Assuming practicality is your main concern, I would suggest two points to consider.
1. Follow O Meien's advice as in his following table:
* Advantage of first move = half the value of a move
* Margin of error = half the advantage of first move
* If it is the opponent’s turn to play, even if you add the advantage of first move and the margin of error to the opponent’s territory, if you are ahead you have “certainty.”
* If there is an outstanding big move for the opponent, assume he can play there then count. Add the advantage of first move to your territory and add the margin of error to the opponent’s territory.
He gives several worked examples and one of them (at least) includes a double-sente issue in the above context just like the one you give.
2. Sente has too many meanings in English. I think you may find a clearer path if you think of the initiative for the global context and sente only for local boundary plays.
O Meien does not talk directly about the initiative, but his book, after all, is about absolute counting. However, who has the initiative can be assessed in additional ways to strict counting (e.g. number of mistakes made so far, weak points/groups etc - and for this QARTS is useful), so in practice you don't really need to worry about fancy terms such as temperature.
I suppose what it comes down to is that you have to decide what you main focus is: mathematics or playing actual go. It's too much of a handful to have both.
Assuming practicality is your main concern, I would suggest two points to consider.
1. Follow O Meien's advice as in his following table:
* Advantage of first move = half the value of a move
* Margin of error = half the advantage of first move
* If it is the opponent’s turn to play, even if you add the advantage of first move and the margin of error to the opponent’s territory, if you are ahead you have “certainty.”
* If there is an outstanding big move for the opponent, assume he can play there then count. Add the advantage of first move to your territory and add the margin of error to the opponent’s territory.
He gives several worked examples and one of them (at least) includes a double-sente issue in the above context just like the one you give.
2. Sente has too many meanings in English. I think you may find a clearer path if you think of the initiative for the global context and sente only for local boundary plays.
O Meien does not talk directly about the initiative, but his book, after all, is about absolute counting. However, who has the initiative can be assessed in additional ways to strict counting (e.g. number of mistakes made so far, weak points/groups etc - and for this QARTS is useful), so in practice you don't really need to worry about fancy terms such as temperature.
I suppose what it comes down to is that you have to decide what you main focus is: mathematics or playing actual go. It's too much of a handful to have both.
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Gérard TAILLE
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Re: Can a double sente position exist?
OK Robert, OC, if you have not developed a nomenclature for class of positions with tentative sente and gote options for both players then you can hardly find a double sente position.RobertJasiek wrote:For this class of positions with tentative sente and gote options for both players, I have not developed a local nomenclature.
Double sente positions can only appear if you try to put a name on all positions including candidates for a double sente status.
BTW you also did not define what a seki is or what a double ko is, did you?
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RobertJasiek
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Re: Can a double sente position exist?
This is not specific to O Meien but common in modern endgame theory.John Fairbairn wrote:O Meien's advice [...]
* Advantage of first move = half the value of a move [...] If there is an outstanding big move for the opponent, assume he can play there then count.
Temperature is not a fancy term but a shortcut for "value of the largest move elsewhere" and as a word a good metaphor for its meaning. We use go terms to express things more efficiently. It is more efficient to say "temperature" than to say "value of the largest move elsewhere" all the time.fancy terms such as temperature
Maybe your disliking of the term comes from your disliking of its mathematical origin. "God forbid, in some respects, mathematics to be more useful than professional", might be your thinking, but this is your personal preference, not something everybody must share.
During the late endgame, in which Gerards example is, a margin of error does not introduce anything useful. Quite contrarily, it introduces superfluous information.* Margin of error = half the advantage of first move [...]
During the middle game or early endgame, a margin of error might be useful. I have considered whether I would want to use some as a go player but come to this conclusion: a particular number for a margin of error as a modifier of the temperature does not give me any meaningful information that I would not already have by the awareness that there is some margin of error of unknown size.
While I understand the purpose, the time for calculating the value for this purpose is better invested in more careful direct endgame evaluation and decisions.* If it is the opponent’s turn to play, even if you add the advantage of first move and the margin of error to the opponent’s territory, if you are ahead you have “certainty.”
("Certainty" might also be called a fancy name. You promote it because it comes from a professional. If other certainties in endgame theory come from mathematics, you would reject it, wouldn't you? Become more objective in what you like and dislike!)
Ok, but every meaning has a good purpose. One just must avoid careless use of the word without clarification, as in "local sente" etc., like one must for other ambiguous terms related to life and death, thickness or whatever. You have studied some other terms in greater detail - we endgame students consider endgame terms in greater detail.2. Sente has too many meanings in English.
Application of such a rough theory would make me weaker. It is something to forget rather than advertise.QARTS
Mathematics is our (except you, we know) friend, like professional advice, AI judgements, strong amateur advice and expert advice are our friends for playing actual go if we are serious about becoming stronger. At the same time, we must be aware of the limitations of each source of input. Limitations, however, do not mean uselessness.what you main focus is: mathematics or playing actual go. It's too much of a handful to have both.
(And if you were serious about rejecting maths out of disliking, you should not advertise O Meien's maths or learning values per shapes by heart, either. Instead, you would claim that nothing but intuitive endgame choice would be enough to reach 9p level.)
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Gérard TAILLE
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Re: Can a double sente position exist?
It appears it is just a matter of wording, Xela.xela wrote:I don't think there's a standard term yet. Personally I call it: "This will become double sente when the game temperature drops below <number>". Who gets to play it as sente depends on who plays the move elsewhere which causes the temperature to drop below the threshold.Gérard TAILLE wrote:How do you call this position as a local position?
In that case, to be consistant, instead of saying that the position above is "sente for black" why not saying "this will become sente for black when the game temperature drops below <number1>". In addition, when the game temperature drops below <number2> then this position will become sente for black and reverse sente for white, and finally when the game temperature drops below <number3> then this position will become gote for both players.
I do not see what harm when you keep simple wording as "sente for black" or "double sente"? It is a little mysterious for me.
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RobertJasiek
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Re: Can a double sente position exist?
Except for countless obviously dominated options, a local endgame with one player's gote and sente options is already an infrequent exception in practice. A local endgame with both players' gote and sente options (other than doubly ambiguous) is even much less frequent in practice.Gérard TAILLE wrote:not developed a nomenclature for class of positions with tentative sente and gote options for both players then you can hardly find a double sente position.
From a theoretical POV, you have every right to criticise Bill Spight and me not to have solved go entirely yet. From a practical POV, we can handle the very few local endgames with both players' gote and sente options without having a complete specialised theory for it (yet).
Recall that you entered discussion decades later than me! In 2004 on https://home.snafu.de/jasiek/j2003.html I defined in-seki, from which I derived a definition of seki (I do not have an URL at hand, but it is obvious anyway). For double ko, you find something of 2008 here: https://home.snafu.de/jasiek/ko_types.pdf Later, I made a private attempts for a finer classification of ko types with large ko strings than in 2010 in https://home.snafu.de/jasiek/ko.pdf but concluded that it would amount to about one definition per specific shape.you also did not define what a seki is or what a double ko is, did you?
Needless to say, from 1996 on, there were my predecessors for specialised rulesets, such as
https://home.snafu.de/jasiek/newko.html
https://home.snafu.de/jasiek/ingkolec.txt
https://home.snafu.de/jasiek/ingko_epilogue.pdf
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RobertJasiek
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Re: Can a double sente position exist?
Harm occurs when greater precision is needed or you disrespect others' greater precision by describing it as if they lacked it.Gérard TAILLE wrote:I do not see what harm when you keep simple wording as [...] "double sente"?
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Gérard TAILLE
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Re: Can a double sente position exist?
Do you mean precision for the defintion itself or precision for the various evalutions (counts or move values)?RobertJasiek wrote:Harm occurs when greater precision is needed or you disrespect others' greater precision by describing it as if they lacked it.Gérard TAILLE wrote:I do not see what harm when you keep simple wording as [...] "double sente"?
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xela
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Re: Can a double sente position exist?
The harm occurs when people play their "double sente" moves too early.Gérard TAILLE wrote: I do not see what harm when you keep simple wording as "sente for black" or "double sente"? It is a little mysterious for me.
"Sente for black" is not so harmful. It's one-sided, it's not going to go away (usually!), so you can wait until later.
But "double sente": I need to play that right away, or else the other person will get it! (Not true, but a too-common misunderstanding.)
For example, here's a position from the Lee Sedol-Gu Li jubango, game 5.
After black plays the marked stone, the top centre is now looking like black's territory, so a is "double sente". Back when I was a 5 kyu, I would have played white a immediately. And a lot of my kyu opponents would have obligingly answered at b. In fact, white ended up playing a much later, on move 112.