No. Guesswork is applying the heuristic without attempting to verify it. I won't quote Yang's formula, but of it he writes: "This guarantees that you can either escape into the center or live inside if your opponent cuts off your escape route." Coming from a professional go player, this doesn't sound like "something that might or might not be right," rather it allows the player to view a certain game situation like a tsumego that he knows has an answer. Sorry that it doesn't fit your criteria for a good theory book, but Yang's work is nonetheless quite good. (definition: books that I think are good, i.e., have contents that I want to read).

_________________
Patience, grasshopper.

The idea to either escape or live inside (or connect to a nearby group or possibly to get a ko) is right. But what does it have to do with counting numbers of intersections to see if there are at least L intersections? L does not answer whether an invasion can escape or live. Reading can answer this.

If there is more to the formula than "invade if the space has at least L intersections, don't invade otherwise", please let us know. (You don't need to reveal the formula, but you can describe its structure.)



Interesting topic, but maybe OT in this thread.

Perhaps, but unless absolutely proven, any theory could be argued to be guesswork - something that may or may not be right.

_________________
be immersed

Kirby, I am speaking about a 100% theory (reading determines whether an invasion group lives, except for the sacrifice of non-essential stones etc.) versus a ca. 50% or 60% proverb ("exactly if the space is at least L intersections, the invasion group lives") advertised as "formula" or "theory".

There are actually quite a number of caveats to go along with it. I'll paraphrase minus the magic number of spaces, it can be removed if problematic copyright wise (it really shouldn't be without the piece of information that makes the heuristic work).

1) You're invading on the third line.
2) There are x empty spaces.
3) There are no opposing stones within this area that are below the third line. Stones may be on or above it though.
4) There must be a clear route into the centre.

What differentiates theory from proverb? The level of detail? Let's make sure we are using the same terminology here.

_________________
be immersed

How do you get from "guarantees" to "50% or 60%?"

_________________
Patience, grasshopper.

Boidhre, thanks. Since the "x empty spaces" thing has pretty well defined, specialising border conditions, it is possible that Yang's formula works for these conditions better than the average proverb. Regardless, I would not want to apply it, because the much more generally applicable "verify by reading" method is more successful.

Kirby, a proverb is designed to be flawed. Depending on the proverb, its success rate is somewhere between 50% ("Black | White | a player having four corners loses / wins the game.") and infrequently ca. 90% ("Avoid empty triangles."). Theory is designed to be correct as often as possible (ca. 90% to 100%) and supposed to be complemented by other theory or exceptions for the remaining 10% - 0% of the cases, where a theory is meant not to apply. (E.g., "Do not self-atari your two-eye-formation." is almost 100% correct theory, with the exception of a superko threat in very rare beast positions.)

That was, when I had only Kirby's description, which seemed to apply for all invasions. Now that I have also Boidhre's description, see my other reply.

It seems to me that if we supplement any 'proverb' by the obviously implied (we are go players after all, this is what we do) 'verify by reading' - it will also apply to 90%-100% of the cases, no?

It keeps brining me to the same question over and over - what *is* go theory you speak of?
Its not just an idle question to get you into predicament, Robert - I really think people are talking about different things here. And I would not be surprised that to most of us here, go theory *is* just a series of more-or-less generalized 'principles', sort-of like more formally stated proverbs. But this is not what you are talking about when you say 'go theory', is it?

_________________
- Bantari
______________________________________________
WARNING: This post might contain Opinions!!

This is what I assume it is. I also throw in discussions of specific lines of play that have been studied extensively by professionals and presented to less strong players. It's a shortcut to shapes in specific positions.

No. Proverbs tend to need more than reading. Firstly, throw away the joke proverbs, such as "Black | White | a player having four corners loses / wins the game.", which exist in every of these variants. Secondly, many proverbs need suitable contexts to be meaningful at all. E.g., "Play away from thickness." applies during opening and early middle game, but not any longer during the endgame. For the late middle game, it depends.



Principle <> proverb.

(No time for the fundamental discussion of defining go theory, because, you know, I need to proofread some more go theory of some book.)

I think it always 'depends' on some conditions or other. Doesn't everything? It is hard for me to imagine very many meaningful statements about Go and move choice without some conditionals in there somewhere. Even your definitions are mostly of the form "if (it looks like this, or has this properties, or whatever) then (its called thusly)."

I have not read your theory books (yet! and I will, I promise) but it is hard to imagine you not having a whole bunch of explicit or implicit 'ifs' peppered within the text.

As for defining 'go theory' - I know you are busy, and not trying to get you away from whatever important stuff you do.
Just pointing out that this whole discussion (and others like it) might be pointless because we are all talking about different things and so we are all right in our personal context. Unless we get some common ground going, it might all lead nowhere, with nobody understanding nobody, and nobody getting convinced of anything.

_________________
- Bantari
______________________________________________
WARNING: This post might contain Opinions!!

IIUC, I think that Robert is saying that a proverb can be called "theory" if it is correct more than 90% of the time. This seems like a bit of an arbitrary classification to me, but whatever the case, I think that many would agree that the more often a proverb is correct, the more useful it is.

The tricky part is in accurately identifying how often a proverb/set of guidelines is actually true.

I think this comes back to thinking for yourself, and analytically evaluating whether or not a particular word of advice is applicable in a given situation.

_________________
be immersed

Great. So any general statement which is correct 90% or more of the time is called 'go theory'?
Any yays? Any nays? Any avs? Lets play congress.

_________________
- Bantari
______________________________________________
WARNING: This post might contain Opinions!!

Personally, the precise classification does not matter to me.

_________________
be immersed

Related note -- something I've been wondering for some time:
does anyone have the stats on when the proverb "hane head of two stones" applies (what % of the time)
and when it fails (what % of the time) ?

It can be called 'good go theory', if there is also a good (often implicit) handling for the remaining 10%.

Not sure, but at a guess - maybe 50% of the time? Just taking the number out of my hat, so it can be totally wrong. Might be actually less than that. Or more.

_________________
- Bantari
______________________________________________
WARNING: This post might contain Opinions!!

Well, since the original proverb is Don't look. Hane at the head of two stones, or Without looking, hane at the head of two stones, my guess is that it applies a lot of the time.

Maybe Dave Sigaty will do a database search for us.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.