Re: [Computer-go] History of influence concepts in go

[Robert Jasiek]

On 10.01.2016 20:06, "Ingo Althöfer" wrote:

it seems that different people are using the name "influence"
for different objects/properties.

In the computer go scene, 1-dimensional use goes back to
Albert Zobrist in his doctoral dissetation from 1970.

Where does your framework for "multi-dimensional" influence comes from?


Influence is a well-known term among players but its clear meaning 
remained a mystery until I described in 2011. Before influence was so 
unclear that it was hard, as a player, to know its difference from the 
other related term thickness. Early player understanding of influence 
was as naive as black / white influence light decreasing by distance 
(i.e., it is not really influence but proximity multiplied by some 
radiation function such as 1 or 1/x^2 or Manhattan distance and negative 
for white light and maybe visually blocked by the disks of stones) but 
everybody knew that that was wrong because dead stones do not create as 
much influence as live stones. Early expert system programs used the 
same naive concept, and every programmer would use his own 
implementation of distance and intensity of light. Such light maps give 
colourful maps that are impressive as paintings but close to useless 
because of containing both correct and false information.


Stronger players know that influence and thickness are related to 
strength of the stones creating the influence and solidity of the groups 
of thickness. But what is strength? From traditional Asian go theory, it 
was known that there is some relation between strength and strategic 
concepts such as (little) aji, development directions, board 
partitioning lines, potential for further territory etc. However, a 
systematic assessment of strength was missing.


So I studied the fundamentals of the traditional go theory and noticed 
that several strategic concepts (such as aji) used for thickness and 
influence were just implications of the more basic strategic concepts of 
connection, life and territory. I invented / (for 'life') rediscovered 
degrees of connection, life and territory, distinguished influence (the 
property of affecting other intersections) from thickness / thick shape 
stones (the property of the "strong" stones creating the influence) and 
defined both in terms of degrees of connection, life and territory. 
Territory is optional in the definition and can also be studied 
independently. Territory as a propery makes sense because it makes a 
difference whether influence cannot be used because of being in a 
neutral region or whether it is / can be used for protecting existing / 
making additional territory.


Study a few simple examples of groups of strong stones with a few or 
more opposing stones in the neighbourhood, and you notice that degrees 
of connection and degrees of life can differ from each other. So 
influence / thickness must be described at least by these two degrees. 
Furthermore, the values differ for Black and White, so at least four 
parameters are necessary for a complete description.


You find my informal definitions here
http://senseis.xmp.net/?Influence
http://senseis.xmp.net/?Thickness
or more carefully in my books. For the precise parameters of connection 
and life see

http://senseis.xmp.net/?NConnection
http://senseis.xmp.net/?NAlive

Concepts of proximity should be called 'proximity' while concepts of 
influence should be called 'influence'. Proximity maps / functions do 
not explain influence except for the simplest examples in which all 
stones are alive and the view is clear in every direction.


Computer go can have various study purposes (such as training neural 
nets or predicting the final colour control in a scoring position) and 
some sort of function over all intersections assigning them a single 
number may be convenient for fast numerical training, but do not forget 
that such a simplication trains both correct and false information 
without distinguishing them properly. If we want to become stronger 
players or create stronger programs, we must distinguish correct from 
false information. Therefore, replace 1-dimensional by multi-dimensional 
values if the task is to assess current positions rather than final 
scoring positions, in which one value is sufficient.


--
robert jasiek
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Re: [Computer-go] History of influence concepts in go

[Nick Wedd]

Hello Ingo,

I would assume that Robert is using "influence" as described at
http://senseis.xmp.net/?Influence
I think I was aware of this sense before 1970. It is not one-dimensional: a
shimari is said to radiate more influence along one side than the other.

Best regards,
Nick



On 10 January 2016 at 19:06, "Ingo Althöfer" <3-hirn-ver...@gmx.de> wrote:

> Hello Robert, hello all,
>
>
> > Von: "Robert Jasiek" 
> > On 09.01.2016 22:44, Justin .Gilmer wrote:
> > > influence
> > > = A1 0.3 ...
> >
> > Influence is not a one-value property.
>
> it seems that different people are using the name "influence"
> for different objects/properties.
>
> In the computer go scene, 1-dimensional use goes back to
> Albert Zobrist in his doctoral dissetation from 1970.
>
> Where does your framework for "multi-dimensional" influence comes from?
>
> Best regards, Ingo.
> ___
> Computer-go mailing list
> Computer-go@computer-go.org
> http://computer-go.org/mailman/listinfo/computer-go




-- 
Nick Wedd  mapr...@gmail.com
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Re: [Computer-go] History of influence concepts in go

[Ingo Althöfer]

Hello Robert, hello all,


> Von: "Robert Jasiek" 
> On 09.01.2016 22:44, Justin .Gilmer wrote:
> > influence
> > = A1 0.3 ...
> 
> Influence is not a one-value property. 

it seems that different people are using the name "influence"
for different objects/properties.

In the computer go scene, 1-dimensional use goes back to
Albert Zobrist in his doctoral dissetation from 1970.

Where does your framework for "multi-dimensional" influence comes from?

Best regards, Ingo.
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