Re: [computer-go] April KGS Computer Go tournament

2007-04-07 Thread Nick Wedd

Reminder - it's tomorrow.

In message [EMAIL PROTECTED], Nick Wedd 
[EMAIL PROTECTED] writes
The March 2007 KGS computer Go tournament will be next Sunday, April 
8th, in the Asian evening, European morning and American night, 
starting at 09:00 UCT and ending at about 13:00 UCT.


It will use small boards (9x9 for the Formal division, 13x13 for the 
Open), Chinese rules with 7.5 points komi, and fast time limits (13 
minutes for the Formal division, 28m for the Open).  The Formal 
division will be an eight-round Swiss, the Open, a four-round Swiss. 
There are details at
http://www.gokgs.com/tournInfo.jsp?id=280 for the Formal division, and 
at http://www.gokgs.com/tournInfo.jsp?id=281 for the Open.


Registration is now open.  To enter, please read and follow, as usual, 
the instructions at
http://www.weddslist.com/kgs/how/index.html.  The rules are given at 
http://www.weddslist.com/kgs/rules.html.

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Re: [computer-go] Simplified MC eva luator ¿explained?

2007-04-07 Thread Jason House

Jacques Basaldúa wrote:

Daniel Liu wrote:

An imperfect evaluation has errors. Is the exact value of the error 
known? No.


I have an idea on that I will try to explain:

Given any finite combinatorial game where the ending nodes
have two possible values: win/loss, any node has a winning rate (I 
ignore if there is a better name for that.) defined

as: (# of subpaths ending in win)/(# of total subpaths)
Let's call it W.

(This winning rate can be a simplified version of what
Erik calls underlying ground-truths.)

Assuming two simplifying hypotheses:

1. The playouts are uniformly random.
2. Both players have the same number of legal moves (or any unbalanced 
numbers compensate in the long term).


The unknown probability p of wining a random playout is
a function of W.

The _observed_ proportion after n random experiments, p-hat
is an _unbiased_ estimator of p whose confidence intervals
are the intervals for a binomial proportion as stated earlier
in this list.

Abusing of language, we can call p and estimator of W. (It is
not really an estimator because it cannot be computed directly.)

Now, the most interesting part: p is a _biased_ estimator of W
and it is biased towards 1/2 as long as the expected value of the 
noise is zero (= playouts are not biased). The higher the

noise (or _the longer the playout_) the more biased it is.

In short:
1. We measure p-hat which is an unbiased estimator of p with
known error distribution.

2. p is a biased towards 1/2 estimator of W. Knowing the variance (or 
replacing it by an estimator measured from experiments), we can model 
the bias.


Simplifying to understand why it is biased toward 1/2
add random noise distributed as N(0, e) to p.

With small noise:  p + N(0, 0.01) gives very similar results to p

With big noise:  p + N(0, 100) gives very similar results to 1/2 for 
any p in [0,1]


This is a rather theoretical post of small practical use, but
it helps explaining the effect of the longer playouts = higher 
variance = more biass towards 1/2.


Jacques.

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I don't understand your post.
bias = E(p_hat) - p = E(p+N) - p = E(p)+E(N) - p = p + 0 - p = 0

I'm thinking that maybe you're clipping p+N to [0,1]?  Maybe my biggest 
confusion is how you're actually arriving at p+N in a meaningful way.  A 
single MC playout corresponds to a bernouli trial with probability p.  
Even with many trials, the noise becomes binomial, and asymptotically 
approaches the normal distribution.

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Re: [computer-go] Simplified MC evaluator ¿explained?

2007-04-07 Thread Weston Markham

On 4/7/07, Jacques Basaldúa [EMAIL PROTECTED] wrote:


Assuming two simplifying hypotheses:

1. The playouts are uniformly random.
2. Both players have the same number of legal moves (or any
unbalanced numbers compensate in the long term).



I did not understand your post either.  Is #2 the same as neither player
passes until the end of the game?  Or do you intend to assume that at any
given level of the game tree, all nodes have the same number of children?
The latter assumption seems to be much stronger than what you intend, since
it would imply that p=W exactly.  Plus, it is obviously (and dramatically)
false under any normal go rules where two passes end the game.

Weston
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Re: [computer-go] neural net variant

2007-04-07 Thread forrestc
Has anyone written anything reasonably accessible re

designing a neural net where the pulses themselves carry information (ie a
32-bit piece of bitmap, perhaps)

and/or

that information itself is used in determining whether a cell fires?

Forrest Curo


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Re: [computer-go] The dominance of search (Suzie v. GnuGo)

2007-04-07 Thread Chrilly


I have this idea that perhaps a good evaluation function could
replace the play-out portion of the UCT programs.  The evaluation
function would return a value between 0 and 1 and would be an
estimate of the odds of winning.

I have tried this with an older and much weaker version of Suzie. It played 
positionally better than the Alpha-Beta version, but the rate of very 
strange moves also increased. UCT greates a more unbalanced tree than 
Alpha-Beta and the programm has therefore even more chances to cheat. For 
the same reason extensions do not work so far in Suzie.


But I tried not with 0-1 but used the full eval. Maybe I should give it a 
second try. But as I work now 45 hours/week on Computer-Tomography (which is 
also quite interesting) and comute each weekend between Germany and Austria 
its difficult to do.


Chrilly

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Re: [computer-go] The dominance of search (Suzie v. GnuGo)

2007-04-07 Thread Don Dailey
To take a normal evaluation function and convert it to a 
probability of winning function is probably difficult to 
do well.   You might have to map some sort of curve where
a few stones ahead represent a near win.

A simple approximation: - call the evaluation function - if
it is less than zero, consider it one monte carlo run where
white wins.If it's greater than zero, consider it a 
monte carlo run where black wins.   

It's probably better to use the curve - but my sense of it
is that you need to map scores fairly accurately to odds
of winning - to truly simulate a monte carlo run.

How did you do this before?  I think almost any reasonable
idea is worth 2 or 3 tries - the devil is in the details.

- Don


 

On Sat, 2007-04-07 at 19:52 +0200, Chrilly wrote:
 
  I have this idea that perhaps a good evaluation function could
  replace the play-out portion of the UCT programs.  The evaluation
  function would return a value between 0 and 1 and would be an
  estimate of the odds of winning.
 
 I have tried this with an older and much weaker version of Suzie. It
 played 
 positionally better than the Alpha-Beta version, but the rate of very 
 strange moves also increased. UCT greates a more unbalanced tree than 
 Alpha-Beta and the programm has therefore even more chances to
 cheat. For 
 the same reason extensions do not work so far in Suzie.
 
 But I tried not with 0-1 but used the full eval. Maybe I should give
 it a 
 second try. But as I work now 45 hours/week on Computer-Tomography
 (which is 
 also quite interesting) and comute each weekend between Germany and
 Austria 
 its difficult to do.
 
 Chrilly
 

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[computer-go] MoGo

2007-04-07 Thread Matt Kingston

Personally, I could care less - I guess because I am a chess player and
I think it's weaker players who are impressed most by big wins.   Very
strong chess players tend to take the long way around - taking the sure
win to the dramatic flashy quick but risky win.   Weaker chess players
tend to judge the skill of the player based on how many moves it takes
to win a game but strong players know this is more a matter of playing
style - not skill.

It actually surpises me that go players care about this.  I thought GO
was more about the beauty of ommision and the unstated understanding 
of event that don't actually have to happen to be appreciated.

- Don



It depends on what your purpose is in playing the game in the first place. If 
you're simply aiming to create a program that is able to win against strong 
players, then it makes sense to simply play the move that it thinks is going to 
give it the greatest probability of a win. This makes sense for those 
developing cutting edge go playing programs and trying to achieve the highest 
rank possible.

What I want from a commercial go playing program is one that I can use to learn 
to be a better go player.  This brings up two important deficiencies in the 
win by 0.5 strategy. If I'm always loosing by half a point, It's difficult 
for me to see when I'm playing well and when I'm playing poorly. If the 
computer doesn't exploit my weaknesses because it knows that it will win 
anyway, then I won't learn to defend properly. I'll never know if I almost 
won or if the computer was just toying with me the whole way. The feedback 
from the computer just killed everything can help me play better.

Secondly, we learn by emulating better players (though some may disparage blind 
emulation, it's easier to learn why a certain play is good if you're using it 
in your own games.) If the computer gets comfortably ahead then plays strange 
moves, it's difficult for me to learn normal proper endgame moves by watching 
the computer play.

Maybe it will be better when a commercial version of MoGo is available and I 
can turn the difficulty settings way down so that I have a chance to actually 
win a game or two. Are there any plans for a commercial version of MoGo?


 


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Re: [computer-go] The dominance of search (Suzie v. GnuGo)

2007-04-07 Thread Chrilly


I don't understand your question.   I don't claim non-determinism
helps with alpha beta and I'm not recommending a fuzzy evaluation
function, I'm just saying it still works.  A deeper search will
produce better moves in general.

One has the randomness anyway. A heuristic evalution can be considered as 
the sum of a systematic term which is an estimator of the true evaluation 
and an error term (and a bias).
One consequence of this model is, that the shape of the search tree has a 
significant influence on the evaluation. The programm will favour variations 
where it has a lot of good moves and the opponent has only a few. Because 
the more (good) moves the program has, the higher is the expected value of 
the error terms. The programm has more tickets in the error-term lottery.


I have noticed this effect constantly.  E.g. if one extends captures, the 
programm tends to favour lines with captures, if one extends checks 
stronger, the program likes to check...


Chrilly

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Re: [computer-go] The dominance of search (Suzie v. GnuGo)

2007-04-07 Thread Chrilly
There is a chapter in Ulf Lorenz Dissertation about this topic. Ulf mentions 
this aspect also in  the Hydra papers. E.g. the one for the XCell Journal. 
Search on the net for Lorenz, Donninger, Hydra and format pdf. But in 
this papers the concept is only mentioned without a detailed 
proof/explanation. This is only done in the Diss.
The title of the Diss. is: Ulf Lorenz: Controlled Conspiracy Number Search, 
Paderborn 2000. But the work is in German.
After the match Adams-Hydra Ulf wrote a longer article about his 
error-filter theory for the ICGA-journal. But the article was rejected.


Ulf has used this model for a project to improve the robustness of 
airplane-schedules. The current algorithms just optimize the scheduling of 
airplanes (and the crew), but they have usually no notation of robustness. 
If there is a delay in London, then the flight Frankfurt Paris might be 
delayed too, because according the schedule the airplane is used after the 
return from London in Frankfurt for the Paris fligth. And this can in turn 
delay the flight from Paris to Madrid, because the crew has now - according 
the law - to take a rest in Paris, but the scheduling programm calculated 
that its optimal that they are also on board for Paris-Madrid and take the 
rest in Madrid
One can consider the time according schedule as a noisy evaluation function 
and can try to find more robust solutions which is not much worse than the 
best solution. Its a conspiracy approach for scheduling problems.


Chrilly

- Original Message - 
From: Darren Cook [EMAIL PROTECTED]

To: computer-go computer-go@computer-go.org
Sent: Saturday, April 07, 2007 2:18 AM
Subject: Re: [computer-go] The dominance of search (Suzie v. GnuGo)



(R==1). An incorrect pruning decission is not taken forever.  The
general idea is to use information from the search tree to shape the
search tree. Ulf Lorenz from the Univ. Paderborn considers the search
tree as an adaptable error filter.
...

UCT and Monte Carlo.   It's not as much Monte Carlo any longer.

Yes, ecaxtly. I also think that the difference is fuzzy. Both methods
fit into the adaptable error filter model of Ulf.


Hi Chrilly,
Do you have a recommendation for a good paper to read on this? Ideally
one that doesn't need specialized chess knowledge to appreciate, but I
may not have a choice: google is giving me 0 hits on adaptable error
filter.

Darren


--
Darren Cook
http://dcook.org/mlsn/ (English-Japanese-German-Chinese free dictionary)
http://dcook.org/work/ (About me and my work)
http://dcook.org/work/charts/  (My flash charting demos)
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Re: [computer-go] professional knowledge

2007-04-07 Thread Ray Tayek

At 06:17 AM 4/6/2007, you wrote:

On Fri, 2007-04-06 at 13:48 +0100, Jacques Basaldúa wrote:
 Darren Cook wrote:

   All except joseki-knowledge is board-size independent.

 Maybe human player's adapt to different board sizes without
 even noticing. But if you try to model strategy with algorithms
 it is totally board size dependent.

Doesn't that just imply the model is incorrect?   If the model
captures the true spirit of the game, it shouldn't matter.


There may be some formal (but likely complex) way to describe a
correct opening play strategy on any size board that is not
board-size dependent.


mr. yang uses the ideas of short and long 
extensions and high-low combinations in the 
beginning. (a short extension being 1 or spaces 
and a long being ideally 5 spaces). this tends to be eficient.



   I'll try to give an example:

  On small boards, it seems like it's correct to play to the
  center point on the first move?   Why?   The rule: always
  play to the center point might NOT be a board size independent
  strategy but might work well for boards smaller than say 11x11.
  But if you could capture the REASON for this,  you might be
  able to formulate a better strategy for playing the first
  move that would work on all boards.


playing in the center on a large board is 
reasonable. the trick is to make the stone 
useful. on a large board, this leads to an 
unusual style of play. black wins all ladders and 
has an advantage in all fights. many josekis are unfavorable for white.



There are underlying reasons for everything and that is what must
be captured to achieve a boardsize independent strategy.

Of course I'm getting rather theoretical.  I understand that you
are looking for practical solutions and approximations.


i suspect that the short/long and high/low 
heuristic would be useful during the fuseki stage.


thanks

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[computer-go] LISP question (littlle bit off topic)

2007-04-07 Thread Chrilly
Up to my knowledge the first Lisp Versions had no number system. The number n 
was represented as the list of numbers from 1 to n (which is also the 
mathematical/axiomatic definition of the natural numbers). 
But its not very practical. Can anyone provide me with a link how this was 
done. I am speaking some computer languages, but Lisp is not among them.
I want to present the code in an article for the Austrian AI-Journal (as an 
example that mathematical elegance and practically usefull are 2 different 
things).

Chrilly
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Re: [computer-go] LISP question (littlle bit off topic)

2007-04-07 Thread Peter Drake
I don't have a reference, but it's probably a variant of Church  
Numerals:


http://en.wikipedia.org/wiki/Church_numeral

On Apr 7, 2007, at 12:54 PM, Chrilly wrote:

Up to my knowledge the first Lisp Versions had no number system.  
The number n was represented as the list of numbers from 1 to n  
(which is also the mathematical/axiomatic definition of the natural  
numbers).
But its not very practical. Can anyone provide me with a link how  
this was done. I am speaking some computer languages, but Lisp is  
not among them.
I want to present the code in an article for the Austrian AI- 
Journal (as an example that mathematical elegance and practically  
usefull are 2 different things).


Chrilly

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Re: [computer-go] LISP question (littlle bit off topic)

2007-04-07 Thread Don Dailey
On Sat, 2007-04-07 at 21:54 +0200, Chrilly wrote:
 Up to my knowledge the first Lisp Versions had no number system. The
 number n was represented as the list of numbers from 1 to n (which is
 also the mathematical/axiomatic definition of the natural numbers). 
 But its not very practical. Can anyone provide me with a link how this
 was done. I am speaking some computer languages, but Lisp is not among
 them.
 I want to present the code in an article for the Austrian AI-Journal
 (as an example that mathematical elegance and practically usefull are
 2 different things).

There are also elegant (and minimal) computer languages that are turing
complete, but nobody want to program with them - they are not practical.


- Don


 Chrilly
  
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Ang: [computer-go] LISP question (littlle bit off topic)

2007-04-07 Thread [EMAIL PROTECTED]
 You are looking for a formalization of natural numbers.
 The one you describe is probably a mangled description of the 
construction from set theory.
 AFAIK The natural Lisp construction is from the Peano axioms.
 A shallow discourse:
 http://en.wikipedia.org/wiki/Natural_number#Formal_definitions

MvH Dan Andersson
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Re: [computer-go] professional knowledge

2007-04-07 Thread forrestc

 mr. yang uses the ideas of short and long
 extensions and high-low combinations in the
 beginning. (a short extension being 1 or spaces
 and a long being ideally 5 spaces). this tends to be eficient.

There is the classic Chinese rule of thumb on how far one can comfortably
extend along an edge: 2 spaces from one stone, 3 from a perpendicular pair
of stones, etc--But then a high-rank professional published an English
book some years back where one chapter dealt with what the optimal
extension from one stone would be in practice. It turned out highly
situation-dependent, from one to five spaces, with the 2 space rule
applying only in isolation from other considerations.

And probably this too is board size dependent: How much is there
potentially to gain by abandoning the connection and running with one side
of the position?

Forrest



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Re: [spam probable] [computer-go] MoGo

2007-04-07 Thread Sylvain Gelly


I can turn the difficulty settings way down so that I have a chance to
actually win a game or two.


You can always decrease the time per move and at some limit, you'll reach
random play. Even if I can't win against MoGo with 300 playouts per move (I
am so bad :-( ), but can I beat a random player? :-)


Are there any plans for a commercial version of MoGo?



No, at least in near future.

Sylvain
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[computer-go] From Surreal Numbers to Games

2007-04-07 Thread Ray Tayek

fyi:

http://scienceblogs.com/goodmath/2007/04/post_3.php


Today we're going to take our first baby-step into the land of surreal games.

A surreal number is a pair of sets {L|R} where 
every value in L is less than every value in R. 
If we follow the rules of surreal construction, 
so that the members of L sets are always strictly 
less than members of R sets, we end up with a 
totally ordered field (almost) - it gives us 
something essentially equivalent to a superset of 
the real numbers. (The reason for the almost is 
that technically, the surreals form a class not a 
set, and a field must be based on a set. But for 
our purposes, we can treat them as a field without much trouble.)


But what happens if we take away the restriction 
about the  relationship between the L and R 
sets? What we get is a set of things called 
games. A game is a pair of sets L and R, where 
each member of L and R is also a game. It should 
be obvious that every surreal number is also a 
game - but there are many more games than there 
are surreal numbers, and most games are not surreal numbers.


Games lose some of the nice properties of the 
surreal numbers. They are not a field. They are 
not totally ordered. In fact, they're not even 
all positive or negative. They're very strange things.


So why would we want to break the restriction on 
the surreals that gives us games? Naturally, 
because games have useful applications in 
modeling many things - in particular, games (in 
the non-mathematical sense - games like Go, Chess, Checkers, Poker, etc).


Let's take a bit more of a detailed look at games, and how they interact.

Game arithmetic is exactly the same as surreal 
arithmetic: addition, subtraction, 
multiplication, negation - even division (which 
we haven't looked at yet) are all defined in the 
same way of surreal numbers and games.


But: while surreal numbers are always either 
positive, negative, or zero, games can also be 
fuzzy. Remember, games are not fully ordered. 
That means that there are pairs of games (a,b) 
where ¬a b and ¬b a - that is, where the two 
games cannot meaningfully be compared. Fuzzy 
games are games that can't be compared to zero.


What does a fuzzy game look like? The simplest 
example is: {1|-1}. Try to use the definition of 
  on that game with zero - it doesn't work.


Games also have some strange behaviors with 
respect to multiplication. If a, b, and c are 
games, then (as you would expect for numbers), if 
x×z=y×z then x=y. But, with games, x=y doesn't 
mean that x×z=y×z. Nasty, that, eh?


So what are these beasts useful for? Part of 
Conway's motivation was trying to analyze the 
game of Go (aka Wei-Chi). Go is one of the oldest 
strategic games in the world; it's been played 
for thousands of years in China, Japan, and 
Korea. Go is the Japanese name, which is 
generally used here in the US; Wei-Chi is the 
chinese name for it. It's a thoroughly fascinating game.


Go is a two-player game where the players have a 
17x17 grid. Each move, a player puts a piece of 
their own color on one of the intersections on 
the grid. The goal of the game is to surround 
territory using your pieces. Whoever has the most 
territory at the end wins. Mechanically, it's 
about as simple as a game can get. Strategically, 
it's unbelievably deep and complex. It's 
frequently compared to Chess in terms of depth 
and strategy. It's a wonderful game. ...



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Re: [computer-go] MoGo

2007-04-07 Thread Don Dailey
On Sat, 2007-04-07 at 14:36 -0400, Matt Kingston wrote:
 What I want from a commercial go playing program is one that I can use
 to learn to be a better go player.  This brings up two important
 deficiencies in the win by 0.5 strategy. If I'm always loosing by
 half a point, It's difficult for me to see when I'm playing well and
 when I'm playing poorly. If the computer doesn't exploit my weaknesses
 because it knows that it will win anyway, then I won't learn to defend
 properly. I'll never know if I almost won or if the computer was
 just toying with me the whole way. The feedback from the computer
 just killed everything can help me play better.

Hi Matt,

I have heard this argument before, but I personally do not 
subscribe to it.  Please let me explain why.   

Of what learning purpose is it if you are losing the game and
the computer gets you to focus on a dramatic battle somewhere
that is totally irelevant?   What are you being taught?  I
think you would develop the wrong sense of the game.  Instead
of thinking and planning for a win, you would be thinking and
planning for local battles - and as UCT and MC have shown us,
this is the WRONG way to think about the game.   

In fact this is how beginners think about the game.  It doesn't 
seem to me like a good learning aid to try to get the computers
to emulate the losing strategy weaker players use.   

I don't think this is a theoretical discussion either, because
when I'm testing and watching Lazarus play I learn already
from watching this masterful strategy.   

In fact, I've come to prefer this style.   It somehow makes
the program seem more mature - less like a child.   A mature
adult does not find pleasure in the foolish things a child
might - but instead gradually learns what is important.  

And go really is all about that - knowing what is really
important and what is not and I would rather learn from a 
player who demonstrates that to me.

- Don


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[computer-go] The physics of Go playing strength.

2007-04-07 Thread Don Dailey
A few weeks ago I announced that I was doing a long term
scalability study with computer go on 9x9 boards.

I have constructed a graph of the results so far:

  http://greencheeks.homelinux.org:8015/~drd/public/study.jpg

Although I am still collecting data, I feel that I have
enough samples to report some results - although I will
continue to collect samples for a while.

This study is designed to measure the improvement in
strength that can be expected with each doubling of computer
resources.

I'm actually testing 2 programs - both of them UCT style go
programs, but one of those programs does uniformly random
play-outs and the other much stronger one is similar to
Mogo, as documented in one of their papers.

Dave Hillis coined the terminolgoy I will be using, light
play-outs vs heavy play-outs.

For the study I'm using 12 versions of each program.  The
weakest version starts with 1024 play-outs in order to
produce a move.  The next version doubles this to 2048
play-outs, and so on until the 12th version which does 2
million (2,097,152) playouts.  This is a substantial study
which has taken weeks so far to get to this point.

Many of the faster programs have played close to 250 games,
but the highest levels have only played about 80 games so
far.

The scheduling algorithm is very similar to the one used by
CGOS.  An attempt is made not to waste a lot of time playing
seriously mis-matched opponents.

The games were rated and the results graphed.  You can see
the result of the graph here (which I also included near the
top of this message):

  http://greencheeks.homelinux.org:8015/~drd/public/study.jpg

The x-axis is the number of doublings starting with 1024 
play-outs and the y-axis is the ELO rating.   

The public domain program GnuGo version 3.7.9 was assigned
the rating 2000 as a reference point.  On CGOS, this program
has acheived 1801, so in CGOS terms all the ratings are
about 200 points optimistic.

Feel free to interpret the data any way you please, but here
are my own observations:

  1.  Scalability is almost linear with each doubling.
 
  2.  But there appears to be a very gradual fall-off with
  time - which is what one would expect (ELO
  improvements cannot be infinite so they must be
  approaching some limit.)

  3.  The heavy-playout version scales at least as well,
  if not better, than the light play-out version.

  (You can see the rating gap between them gradually
  increase with the number of play-outs.)

  4.  The curve is still steep at 2 million play-outs, this
  is convincing empirical evidence that there are a few
  hundred ELO points worth of improvement possible
  beyond this.

  5.  GnuGo 3.7.9 is not competive with the higher levels of
  Lazarus.  However, what the study doesn't show is that
  Lazarus needs 2X more thinking time to play equal to
  GnuGo 3.7.9.


This graph explains why I feel that absolute playing
strength is a poor conceptual model of how humans or
computers play go.  If Lazarus was running on the old Z-80
processors of a few decades ago, it would be veiewed as an
incredibly weak program, but running on a supercomputer it's
a very strong program.  But in either case it's the SAME
program.  The difference is NOT the amount of work each
system is capable of, it's just that one takes longer to
accomplish a given amount of work.  It's much like the
relationships between power, work, force, time etc.  in
physics.

Based on this type of analysis and the physics analogy,
GnuGo 3.7.9 is a stronger program than Lazarus (even at 9x9
go).  Lazarus requires about 2X more time to equalize.  So
Lazarus plays with less force (if you use the physics
analogy) and needs more TIME to get the same amount of work
done.

ELO is treated numerically as if it were work in physics
because when it's measured by playing games, both players
get the same amount of time.  The time factor cancels out
but it cause us to ignore that it's part of the equation.

On CGOS, Lazarus and FatMan are the same program, but one
does much more work and they have ELO ratings that differ by
almost 300 ELO points.   Even though they are the same 
program you will look on CGOS and believe Lazarus is much
stronger because you have not considered the physics of Go 
playing strength. 

- Don


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