Ko / Discussion

Sub-page of Ko

 Table of contentsKo on SL Explaining rule and situation at once Discussion starting on 2009-12-07

Ko on SL

The whole ko issue, essential to the understanding of the game, is poorly structured at SL. We have a couple of good pages, which are basically the central pages ko and ko-threat but they unfold into several paths which promise to be more exhaustive and thorough, for either beginners or experienced players. Those promises are rarely kept and instead many of the pages repeat what is said in a less understandable way.

That's my opinion of course. Dieter

Ben Axelrod: I agree, as a beginner with no local Go club it took me a long time to understand ko threats and ko fighting even with SL as a guide. I think a simple, step by step example on a 9x9 board should be put onto the BasicsOnKos page. There should only be a few, very distinct ko threats. This would only benifit beginners because more advanced players would be able to read ahead... but beginners lack this ability, and i think it helps to se it played out. For the more advanced players, perhaps some consolodation on the many pages related to Ko.

Explaining rule and situation at once

sam: Isn't it easier to say "Ko is a rule that says that you cannot exactly recreate the board as it was at the end of your last turn." ? That both defines the ko situation, and the rule. What we have now doesn't make sense, unless you know what a Ko is, and if you do then you don't need the definition given?

Discussion starting on 2009-12-07

RobertJasiek, 2009-12-07: As I have proven formally and mathematically for all positions, each string in each position can be captured in a cycle when no ko rules are being applied. Therefore the suggested definition is effectively saying that each stone on the board is a ko stone. That Ing made the same mistake in his rulesets is not justification for repeating it on this webpage. - Currently I am trying to define ko in general (i.e., for ko strings of any size). It is very difficult though and I do not know when I will be finished with it. One thing is already very clear though: A good definition must depend on the term force. I.e., as an interim solution, the rough description on this webpage should either explain basic ko only or refer to an aspect of "necessarily", "force" or something like that.

Herman: This article does describe basic ko. Note that the first line says "It describes a situation where...", not "It describes all situations where". All such situations are covered in the Cycle article.

RobertJasiek: If this page is supposed to describe only basic ko, then its page title needs to be changed to Basic Ko. If this page shall describe all kos, then the contents must fit the intention. Do not hide knowledge. Explain it. Ko and cycle are different concepts. Therefore one should not explain ko on a page titled Cycle. That page must explain what a cycle is.

Herman: The word "Ko", in normal usage, refers to the basic ko. It is only in the context of go rules theory and different rule sets ko rules that is is referred to as "basic ko". Tsumego books do not label problems as "Black to play and make basic ko". If a line of play ends in eternal life, books do not label it as "the result is ko". Thus, the page title is fine. That does not mean we cannot refer to other ko rules, or ko types here, but it should not be the main content of this page. Instead, such content should go in separare articles and can the be referred from here. The cycle article deals with all repetitions, and with the rules associated with them, and is a good starting point for anyone who wants to gain a deeper knowledge of such issues. Another article for this is ko rules, but that definitely need cleanup to be usable. I've added links plus explanation at the top of the page.

isd: I agree with Herman, it is not acceptable to make up your own terminology on Go and force it upon Senseis Library. This page should be called Ko and not Basic Ko, which could, and in reality does, have several meanings.

RobertJasiek: Most books do not teach anything else than basic ko, which they call ko. Some problem books have a few problems for big kos like eternal life. A small number of practical go theory books explain some of the big ko shapes. In English, more rules booklets than practical go theory books do so. In general, the entire printed literature about ko is pretty weak. Online messages and webpages teach more. Therefore relying on only printed sources means to rely on weaker knowledge than possible. In all texts, usage of "ko" as a term for something visible on the board has been used in two different ways: 1) for objects of any size, 2) for basic kos only. This page must explain at least that both ways exist. Otherwise it keeps the reader dull intentionally. That much new knowledge has arisen from a context of go rules studies does not mean that it cannot be useful outside that context. isd, if you dislike my terminology, then use another instead. But do not abuse your personal preference for hiding new knowledge! You should realize that currently most new knowledge about ko comes from rules research, definitions of terms research or value theory and that I contribute a good percentage of that. In particular, I introduce and define terms that everybody else has overlooked entirely. Preventing those terms from Sensei hides knowledge. Tell me what is wrong with calling both ordinary kos and big kos "kos"! I consider such language to be very efficient! Much more than explaining "A round-robin-ko is not a ko but (...something else).", what you appear to favour. Calling a ko not a ko, really. You confuse people by rejecting my usage of "ko"!

isd: no, you are wrong. You offer no evidence at all that what you say is true. Have you researched the Japanese/Chinese/Korean texts on rules? If not how can you claim your research is new? Well you can not claim this. You are probably referring to your own research, to which you offer no claim of merit or accuracy. It is quite obvious that one can elaborate on the nature of ko, it is quite obvious that ruining the ko page to do so is a bad idea. Create a new page for your possibly unique ideas, that is a much better idea. I do not know what the phrase But do not abuse your personal preference for hiding new knowledge! is supposed to mean, nor did I know that I had such a preference.

RobertJasiek: isd, actually I have seen some Japanese/Chinese/Korean texts on rules without being able to read the text directly. Some of these were translated into English and I have read the English versions and compared them visually with some of the originals. Positions of diagrams, occurrences of characters I can recognize and paragraph structure allow me to judge that the translations have been reasonably close. Some of the Oriental texts I have been told what their contents is. For others I see at least the go diagrams and can conclude what their contents is missing. Yet much more importantly, I see the effects of what must be missing: For countless things I have found by my own research, no hint whatsoever transpired that it might already have existed elsewhere. Rather many hints were available that showed conceptual confusion because of previously missing knowledge. Of course, I cannot be 100% sure but nobody has offered any example so far where, what I consider first discoveries in rules research by me, it would have been discovered in East Asia before.

kb: Robert, I think you will find that the only person who uses your described version of ko is you. That's because ko isn't defined like you say it is... No amount of talking about how this or that ko is basic, hyperactive, two-step, approach, rogue, etc., does not make these kind of capture-recapture (e.g. sending two returning one) ko. It is your viewpoint only.

There is a big difference between a ko on the board and what is called the "ko rule" or the "superko rule", which is perhaps wrongly named, since this rule governs infinite repetition in general, not a ko. A ko is just one type of infinite repetition.

I also agree completely with ThorAvaTahr's comment below this one.

RobertJasiek: Your limited knowledge about usage of the term ko lets you make a very wrong conclusion. Sensei is not representative for the usage.

RobertJasiek: There is a big difference between ko on the board and ko rule(s) as much as there is a big difference between ko on the board and cycles possible in it. Since ko rule(s) is so misleading, long ago I have suggested to speak of restriction rules (the other restriction rules about passes or (no) suicide also influence what a ko is and how good play in it is). Kos are the type of potential infinite repetition that are relevant in some sense.

ThorAvaTahr: Robert, you claim to be striving for spreading human knowledge, however your attempts have the averse effect. Please do not be offended by hermans and isd's suggestions to move your detailed analysis of ko to a specialized page. I agree with them that ko as it is used in common language by many go-players refers to what you like to call basic ko and a context related to basic ko. I strongly think that a median visitor of senseis that is looking for a page named "ko", looks for an overview page of basic ko and may want to be linked to more indept pages from there.

To speak more strongly: If you add information about advanced concepts here, while using terminology not known by general go-players, you will mystify the entire page, making it unreadable for general go-players. In fact you will be concealing all knowledge about ko by this. So please, allow herman and isd to master edit this page and make a page yourself which they can link to.

RobertJasiek: This page needs a WME anyway. However, calling this page Ko and wanting only basic information about ko here suggests that the page title ought to be Basic Ko Information or Introduction to Ko. Wikipedia has a very strong sense for putting only that contents on a webpage that agrees to its title. Unfortunately, Sensei still lacks this fundamental good practice of wikis. The page title Ko without any restriction suggests that it would be about ko in general. Why do you fear a general treatment of ko here? Can you not imagine to start with the basic ko shape, then to remark that that would be all beginners need to know, then to describe in a summarizing style that ko in general includes also big kos with inherent long cycles? There is no need to make this page specialized but it must mentioned that there are also kos with long cycles or kos with both 2-move cycles and long cycles.

Herman: Wikipedia would in fact support this page title and content under their Precision and Disambiguation and Primary Topic policies. Wikipedia would use the current page title and content, and disambiguate with a "hatnote" (which is what I've already done).

isd Yes. If one wants to create a mathematical type 'logic' based discussion of ko it should be done elsewhere on a new or separate page. This page is a good summary of ko. It gives a clear list of departure points where one can study further about ko and (super)ko rules. It is not helpful, nor desirable to impose a minority definition of ko upon the text here. As a side note, discussion about page contents should be done using the discussion threads accessible from the top of the page.

Bill: Robert: "As I have proven formally and mathematically for all positions, each string in each position can be captured in a cycle when no ko rules are being applied." That is not true for even cycles of board plays, which is one reason, IMO, to define superkos as repetitive even cycles of board plays. :)

RobertJasiek: Concerning the proof, of course; passes are used. - You will be surprised how I will define ko in general:) For a first few hints, see rec.games.go. I am still struggling with capture-2-return-1 though, more than with quadruple ko stones... Maybe history or prologues have to be taken into account.

RobertJasiek: I suggest to replace the very misleading "It describes a situation where, without the ko rule, the game may not progress due to infinite repetitions." by "It describes two adjacent intersections where two successive single stone captures could recur.".

isd: That sounds like a terrible and confusing sentence to me. The current sentence is neither misleading nor inferior. You may as well argue that teaching a student about newtonian dynamics is misleading.

RobertJasiek: The prior sentence "It describes a situation where, without the ko rule, the game may not progress due to infinite repetitions." is very misleading because a) "situation" is used in a seemingly informal sense while it actually is a term (situation), b) "the ko rule" wrongly suggests that there would always be only one ko rule and that it would always be the same ko rule, c) "may not" should be "might not", d) a just slightly careless reader is encouraged to overlook that, without any applied ko rules, all stones on the board (in a ko or not in a ko) can be captured in recurring cycles.

isd: Again this is just propaganda on your part. You have no interest in improving the page, only in changing it to reflect your own personal preferences. This is not desirable or helpful.

RobertJasiek: Propaganda is what you are doing by this statement of yours: Opinion without factual reasons. In comparison, my reason (d) relies on a mathematical proof, i.e., it is beyond personal preference. My interest in improving the page by replacing "the ko rule" by "some ko rule" or "some ko rules" or "a ko rule" or "e.g., the basic ko rule" lies in informing the page's reader as correctly as possible. Quite contrarily, you want to mislead the reader by pretending an unjustified usage of the definite article.

Herman: The ko rule, in this article, is very well defined. The definition is given in the very next section, which in fact contains "the ko rule" in it's section title. The ko rule as defined on the page is compatible (as a subset) with all major ko rules, but is a simplification which leaves out complications best handled in more specific articles.

isd: I agree, this has been stated already. This is the best way for the article to be written. It is best encyclopedic practice. I support it. This does not mean that I do not support additional articles on ko. or an article on ko entirely from Roberts viewpoint.

RobertJasiek: Herman, and this contines to mislead the reader, although on a greater scale of a concept for the whole page. (It is a question for rules experts whether the stated rule is compatible (as a subset) with all major ko rules or whether some of them mean the 2-play rule with passes in between allowed rather than the 2-move rule.) isd, the best encyclopedic practice is to always be factually correct: both locally and globally.

RobertJasiek: What 12.42.51.28 calls "confusing propaganda" (that "some ko rule" prevents a cycle) is much closer to the truth than that there would always be "the ko rule". In fact, it can be either the one ko rule (if it is a) superko or b) a basic ko rule used as an incomplete set of ko rules) or the ko rules (if cycles are restricted by more than one ko rule, e.g., like it is done in Japanese style rules with their basic ko rule, long cycle void game rule and pass for ko rule). So actually the desinformation is on 12.42.51.28's side when pretending that necessarily it would always be only one ko rule.

isd: 213.73.118.175 argues that his confusing propaganda is giving the reader the truth. However the truth is not hidden from the reader. It is available in the page as he continues through it. What is presented here is what a first time reader would most likely want to know. An experience player might come here looking for something else, but they too would quickly find it in the sub sections/links below. In short, 213.73.118.175 repeats the same propaganda again, but does not advance his case.

RobertJasiek: The page should be correct from its beginning to its end. If a newbie starts with correct information, it will be easier for him to understanding also following correct information.

isd: This is obvious bunkum. Who in their right mind would advocate the presentation of post doctoral level to a kindergarden student? Perhaps only you?

The article is exactly as it should be. Introduction. Progression. Further Information. Bravo! It is well written. Please lets drop this propaganda Robert.

RobertJasiek: This page is like what a beginner learns by himself as a 15 kyu: Partly wrong information for that later he will need to invest great efforts to unlearn it. It is better if he learns good strategy right from the beginning. The article should be: correct introduction, correct progression, correct further information. Then it would be well written.

ThorAvaTahr: I have changed "the ko-rule" into "a ko-rule". I suggest that anyone who finds this too vague rephrases the entire sentence. It is not appropriate to speak of "the" ko-rule, since there are many and they are different in each ruleset. However, i think that the added meaning of the entire sentence is minimal. It is only natural that persisting in a repeating sequence would prevent the game to end. The sentence could perhaps emphasize the need for a ko-rule, but it could be phrased better I think. Let me give it a try: "Indefinite repetition is prevented by a ko-rule." or "A ko-rule allows the game to progress by prohibiting indefinite repetition."

Dieter: Robert, Wikipedia has articles on "Wave", one disambiguating and one on the physical object, not one "basic wave" and one called "wave" which is about the wave-particle entity. Even in physics and even in mathematics, there is another driver than factual correctness and formal logic. It is called pedagogy. When I was in second grade, the math class started with "a Ring is a Set with two operators, ..." as if they would take no chances with awakening the math researcher in any of us as soon as possible. Thank Goodness we're beyond that now.

If we use formal logic and mathematical proof as the sole driver of an encyclopaedic site, then this will become a site for people interested in the mathematical formalities behind Go.

There is room for the formal aspect of Go and indeed we should encourage its development and reading. But we should tackle any subject in its colloquial form: an encyclopaedea attempts to familiarize people with a subject, and one of the key techniques is using language they're used to already, to lure them towards the more intricate handling of the subject. Perhaps colloquial speech scares you away and formal treatment has immediately appeal, but for most people, even go players, it is the other way around.

Neither should we be deliberately wrong, by laziness or stubborness. Your strong viewpoints, often deviating from the average viewpoint, are therefore most welcome, because they will force other authors to be very careful and precise in their statements, leading to overall improvement. But I think your statements will only be kept as the main phrasing if they're not only helpful from a factual or formal angle, but also from a pedagogic one.

RobertJasiek: Thanks for the nice summary!

RobertJasiek, 2010-01-12: In view of the recent research, the page needs an update of its contents.

Ko / Discussion last edited by tapir on December 15, 2011 - 22:16