Dieter: adding lost comments on "Ideas on Go theory" (2006-08-09 18:41) [#2062]

Bill: I just want to say, "Great job!" This is really excellent stuff, Dieter. :-)

Deshi comments

(''Octobre 2005: much of the discussion below is not relevant anymore due to a major change in my approach above; cleaning

the discussion is low on my priority list; nevertheless, the comments have been very interesting and rewarding and still have

a lot of value'')

[1] Charles I'm not aware of any principle exactly covering this point. But see make both ends strong.

RobertJasiek: TDerz, as below, "principle" need not have the same meaning as "tautology under 2-value logic" but can also be

used in pretty informal ways. Nevertheless, strategic go theory can be derived from go rules by means of tautologies. This

has become especially possible since the Japanese 2003 Rules. In fact, I have already made first attempts in that direction.

E.g., it is pretty straightforward to define "life-and-death-group". In the Logical Rules of Go Robert Pauli has defined

"2-eye-group". Under the Japanese 2003 Rules this is a concept already on a strategic level. One of the next things to do

will be an attempt to prove when self-atari of a 2-eye-group makes sense. All such is low level strategy. It will take much

more effort to reach high level strategy. OTOH, for other go rules, late yose or specialized ko play have been derived

formally. That is also low level because it is close to the end of alternation, where the strategic complexity is "low". The

same can be said so far about research under the Japanese 2003 Rules. Dieter is more optimistic but should just note that his

principles are not tautologies.

TDerz Dieter, generally I would say, that I cannot derive several of the statements from the rules (R) and principles

(P). We both will agree believing that they are true, but this derives more from 10.000 of played games and is usually heuristics. The term derives from means for me more has to do with, thus not indicating any wrong causality. The best example is

for me The principle of two eyes: This group without two eyes is (also) alive.
With our background we know that we speak about seki, moonshine life etc. being this group.

For principles however, it can hardly be acceptable that both the affirmative and its opposite are true [2], there must be

more, differentiating stuff to it. That is why they cannot be principles.

BTW, I am not a matematician, hence quite ignorant about the subject. I just feel that if these principles were really derivable from the rules, Go was programmable as TicTacToe, Mühle or Reversi. This is not the case.

I know that the principles are inter-dependent, hence they are not axioms.

I agree with the principle of efficiency - because it is very vague! Dieter, I especially like the part about flexibility with regard to keeping options open. This part is very well written.

The problems start already with the The principle of liberties. I cannot increase all my stones liberties, I must decide and sacrifice some stones etc. for i-iv. (Interdependence of principles)

Other points: The principle of two eyes can be derived from R1+ R3 (eyes not explained & including two false eyes?). It is easy to

agree on that.

The principle of connection only necessarily relates to P1 and P3, ''P2 is not

needed''. Points i to iv I also emphasize often to Go learners, then coming to shape for achieving i-iv.

The principle of development

I think the references are actually different: Increasing liberties (P3), establishing a connection (P4), surround empty points (R2) and

creating space to make eyes (P4) are all some kind of development.

Again, well written.

Concepts (C) and proverbs

1. Hane against the contact play. From P2 and P3. (not P4)

Strategy (S)

S0 The enemy's key point is yours (from R3) Why?

From the principle of flexibility (P6) (P2?) ... The key concept in strategy is the balance of territory and thickness, which is guided by the principles of efficiency

(P1) and development (P5). P6?

C2 Thickness: a group of stones which is firmly connected (P4) P5? and which has sufficient eyespace

(P3). P4?

C3 Territory: an area which is surrounded (P4 P5?: no cut possible) by a thick group, and in which the

opponent has almost no chance to create a lving group (P3). P4?

The meaning of stones or urgency (U)

U3 Stones that are close to the opponent's thickness, have little room for development (P5). P6? U4 Stones that are close to your own thickness also have little room for development (P5). P6?

The meaning of areas or size (bigness) (B)

B1 Open areas, with a lot of room for development, are big.(P5) P6?
B3 Areas close to opponent thickness, are uninteresting (B2 and P6?, not AP1) What is the A in AP1?

S12 Build box shaped territories (P1, C2)
I do not understand this term 'box'.

C5 Stones are light when they have a lot of flexibility (P6) P2 ?.

C6 Shape is a characteristic of a number of stones. Determining principles are efficiency (P1) and

P2 (P6). Objectives are P4 (P3) and P5 ... C7 Forcing moves are moves that force the opponent to settle the shape and reduce flexibility (__P2 __)

so that the forcing player can next play according to his opponent's choice.

More technical proverbs

T13 Capture the ladder as soon as possible. (P6) rather C4
T14 Don't try to cut the one-point jump unless it gives a clear advantage (P2, P6) __and

P3+P5__
T16 Don't peep where you can cut (P4, P6) and P5

[2] TDerz I think this comes from Aristotelian logic with its the excluded third. Either Go needs some kind of special fuzzy logic (I think) weighing all kind of interrelated dogma(ta?) & evaluations

against each other, or you could apply logic only retroactivley (playing it out and compare afterwards).

I believe, that even if we could play ALL possible Go games, match them and look for the widest winning path, we had big

trouble to explain why a particular move is good or (relatively) bad. Often it was supposed that perfect play would be around

13 dan. Discussing moves of your own strength (= your own moves) is always difficult and the abstractness, therewith the

discussion of the game becomes more difficult with higher level.

Dieter: Thanks for your comments Tderz. Just one reply for the moment:

The statements Every group with two eyes is alive and There is a group without two eyes that is alive are not each

others' opposite. Groups with two eyes are a subset of alive groups, hence can be complemented with other kinds of groups

(like seki). The converse statement would be there is a group with two eyes that is not alive. Now if that would be

true, I can't call two eyes a principle but must indeed fall back to a heuristic. Your statement is the opposite of ''Only

groups with two eyes are alive'', which is not what my principle says. It's simple logic, really, there is nothing fuzzy

going on here. (Maybe in Go, but not in this particular principle).

The fact that every group with two eyes is alive (cannot be taken from the board) does follow logically from the rules:

- the rule of suicide or the logical rules forbid existence of a played stone without liberties after the possible captured

stones are removed - a player can only play one stone at the time (alternating play) - give a strict definition to an eye then make recurrent extensions of the definition

Since one cannot play inside one eye AND another at the same time, a group with two eyes is alive.

I a not saying I gave an inclusive definition of eye, neither is the derivation of the principle formulated so that no

holes can be found. I am saying such is possible and that from the rules of play/capture/suicide and alternating play, the

principle can be logically derived.

TDerz Dieter, thank you for pointing out the real opposite of the statement, using a NOT instead of the wrong,

misleading without.

WRT your puzzling reference numbers, where they meant to be as I wrote it, or did you mean something, which I interpreted

wrongly?

The principles expressed by the terms flexibility and development for example (seem to) overlap. Moreover, the

explanation for

the higher numbered development comprises lower numbered principles.

Is this intentionally? My honest question (no sandbagging, I'm a mathematic/logic layman) is: shouldn't principles be

independently defined?

Otherwise it would make sense to formulate the ultimate principles "Win this Go game when starting with black" or ''"Make

a draw when given the appropriate komi"'', being built up by the Rules R and all lower ranked principles P. How

much teaching value would it carry? Most probably as much as the all-comprising Do not make mistakes.

Perhaps my argumentation here, to exaggerate the principles and then negate them, looks like eristic dialectic (quarrel), but

I am of the opinion that principles should be rather something more antagonistic (while therewith interdependent) e.g.

thickness vs. light etc. This would make clear that in Go one has to chose all the time: for example is it usually not possible to play a light,

thick, fast developing, all-connecting single move. The better prioritizing derives from imagined future game positions and their evaluations.

Following this argumentation, I conclude (at least for myself) that Go is played by a top-down approach (look ahead,

evaluate and chose moves which most likely lead to the most positive, attractive game position) and not by a __bottom-up

approach__ (be efficient, make liberties & eyes, connect and develop flexible). I admit that very fast Haya-Go might be played this way, although it is difficult to say what we think (and this will

vary very much!).

In so many presentations of good Go players it is emphasized that Go is a game striving for harmony - a good balance of

several(!) mutually excluding concepts. This is not an appeal to authority, rather I think these players express with these

words harmony and balance all that what you start to analyze in detail on this page.

In fact, in view of above, the Principles seem Concepts to me (except P4 Two eyes).

I admit that I also believe that it should be theoretically possible to set up a logical system which completely explains Go

and leads to the winning game (or a draw of two 13-dans). This logic system - if presented to us here and now - could

be so complicated that we would not understand this and(?)/OR it would be another theory which does not help to improve

our game [3]. Diter tries hard to fit something in between those two extremes.

Therewith my argumentation is a little bit inconsistent here (Go is not solvable by logic vs. there is a helping

logical theory based on rules and axioms, not heuristics), this might be due to the complexity of the subject and/or my

laymanship in both Go and logic.

[3] (off topic) Now I am very ignorant and call Combinatorial Game Theory

such a theory of the second type (for me). Are there players who could benefit from it? Is it more than a formal way of

describing what is going on in Yose?

Dear Tderz, thank you for devoting so much time to the project. It is true that the numbering and the references are

confusing and sometimes plain wrong (corrected as of feb 2004 - most of the cross-referencing now undone). Please

continue to comment on it. I highly appreciate the effort.

Dieter

[10] Then, if the played stone has no liberties it is taken off the board'' or considered an illegal move, depending on

whether you allow suicide.

(the above statement has been modified due to discussion below)

ilan: This last statement doesn't make sense to me. Dieter: It allows for suicide and takes care of beginners' confusion about liberties: "Can I play there? I have no

liberties."

ilan: Well, I am still confused. I don't see how you can play a legal move in which the played stone has no liberties even

after captured stones are removed.

Dieter: It's an algorithm really. First remove opponent stones without liberties (not saying there are any). Then your own

(not saying there are any). You can play inside someones eye, but if he has other liberties then your stone is removed.

ilan: OK, thanks, but I still believe that your formulation is confusing. In particular, there is an implicit distinction

between "taken off the board" and "removed" which should be made explicit, that is, in the second case, the move is cancelled

(this actually follows from forbidden repetition, which appears next), whereas in the first case, the move is completed. In

other words, the removed stones do not go to the same places afterwards.

Benjamin: No, he wants to allow suicide (at least with multiple stones), and I think the formulation is

fine. Anyways, nice text! A few months ago I wrote sth. down that is very similar to your text, and I'm quite convinced that

it's the right aproach.

Dieter: Synchronicity: I was pondering the virtues of stone counting when your text fully convinced me of being on the

right track. A few teaching experiments later I am all the more enthusiatic. And Ilan, you're right: allowing suicide but

forbidding repeated board positions partly contradict each other. I will correct this. But anyway I did not want to get into

a rules argument but rather build the fundamental principles of Go upon the rules. I still feel that the fundamentals of Go

are not adequately covered in English literature. Kageyama starts with ladders, but actually ladders and nets are already

techniques above ground level. I do not really think that beginners need a thorough approach, built upon rules, but I do

think it leads to more understanding and less acceptance. Frustration with Kageyama's lack of giving fundamentals (contrary

to his urging to know them) lead me to describe Basic Instinct. Frustration with that article (and another frustrating

attempt at a static treatise about shape? led me to make this page. Benjamin?, although I think you have devoted yourself

to UGS, your proofreadings will be most welcome.

Dear Tderz, thank you for devoting so much time to the

project. It is true that the numbering and the references

are confusing and sometimes plain wrong (''corrected as of

feb 2004 - most of the cross-referencing now undone'').

Please continue to comment on it. I highly appreciate the

effort.

Dieter

[10] Then, if the played stone has no liberties it is

taken off the board'' or considered an illegal move,

depending on whether you allow suicide.

(the above statement has been modified due to discussion

below)

ilan: This last statement doesn't make sense to me. Dieter: It allows for suicide and takes care of

beginners' confusion about liberties: "Can I play there? I

have no liberties."

ilan: Well, I am still confused. I don't see how you

can play a legal move in which the played stone has no

liberties even after captured stones are removed.

Dieter: It's an algorithm really. First remove opponent

stones without liberties (not saying there are any). Then

your own (not saying there are any). You can play inside

someones eye, but if he has other liberties then your

stone is removed.

ilan: OK, thanks, but I still believe that your

formulation is confusing. In particular, there is an

implicit distinction between "taken off the board" and

"removed" which should be made explicit, that is, in the

second case, the move is cancelled (this actually follows

from forbidden repetition, which appears next), whereas in

the first case, the move is completed. In other words, the

removed stones do not go to the same places afterwards.

Benjamin: No, he wants to allow suicide

(at least with multiple stones), and I think the

formulation is fine. Anyways, nice text! A few months ago

I wrote sth. down that is very similar to your text, and

I'm quite convinced that it's the right aproach.

Dieter: Synchronicity: I was pondering the virtues of

stone counting when your text fully convinced me of being

on the right track. A few teaching experiments later I am

all the more enthusiatic. And Ilan, you're right: allowing

suicide but forbidding repeated board positions partly

contradict each other. I will correct this. But anyway I

did not want to get into a rules argument but rather build

the fundamental principles of Go upon the rules. I still

feel that the fundamentals of Go are not adequately

covered in English literature. Kageyama starts with

ladders, but actually ladders and nets are already

techniques above ground level. I do not really think that

beginners need a thorough approach, built upon rules, but

I do think it leads to more understanding and less

acceptance. Frustration with Kageyama's lack of giving

fundamentals (contrary to his urging to know them) lead me

to describe Basic Instinct. Frustration with that

article (and another frustrating attempt at [a static

treatise about shape] led me to make this page.

Benjamin?, although I think you have devoted yourself to

UGS, your proofreadings will be most welcome.