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

2007-04-08 Thread alain Baeckeroot
Le dimanche 8 avril 2007 03:05, Don Dailey a écrit :
 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
Thanks for this interesting study.
[snip]
 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.)
Could'nt the inflexion of heavy curve also mean that the advantage of
heavy play-out disappears when the number of simulation is very high ?
With huge number of simulation the heavy player could become weaker than
the light player, due to the wrong knowledge introduced in the play-out.
Sadly it seems hard to test this (12-13-14) without huge computing power,
a distributed [EMAIL PROTECTED], or a big amount of patience :-) 


 
   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.)
between 10 and 11 the trend changes.

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

2007-04-08 Thread Chrilly

Paper 1 in the list below states:
Numbers were originally implemented in Lisp I as a list of atoms.
and the Lisp 1.5 manual states: Arithmetic in Lisp 1.5 is new

Could you give an example how the number 3 was implemented in Lisp-1 and how 
2+1?


So far I have found only this remarks but not programming examples. It would 
be much more instructive for my article if I could quote these examples.


Chrilly

- Original Message - 
From: Ron Goldman [EMAIL PROTECTED]

To: computer-go computer-go@computer-go.org
Cc: Chrilly [EMAIL PROTECTED]
Sent: Sunday, April 08, 2007 2:23 AM
Subject: Re: [computer-go] LISP question (littlle bit off topic)



Crilly,

I used to program in LISP and had never heard of this, so I did some 
checking. I think this is a misconception from the fact that numbers  were 
considered atoms and hence stored on the list of atoms. Instead  of just 
being a numeric value they consisted of an association list  (e.g. a list 
of atoms) containing a tag to indicate the value was a  number and another 
word with the value. The LISP I Programmers Manual  [1] gives an example:


-1 = (MINUS . (ASSOC NUMB FLO (1.0)))

(In fact LISP I (1960) only supported floating-point numbers, LISP  1.5 
(1961) supported both integers  floats. [2])


As a result of storing values in an association list arithmetic  routines 
had to do several memory references to obtain the numeric  value.


In a paper on the History of Lisp John McCarthy [3] discussed this 
writing that Numbers were originally implemented in LISP I as lists  of 
atoms, and this proved too slow for all but the simplest  computations. A 
reasonably efficient implementation of numbers as  atoms in S-expressions 
as made in LISP 1.5, but in all the early  LISPs, numerical computations 
were still 10 to 100 times slower than  in FORTRAN.


Later versions of LISP [4] used better tagging schemes for numbers  and 
were able to produce compiled code that was as fast (or faster)  then C or 
FORTRAN.


Finally LISP early on had bignums to compute using arbitrary- precision 
integers (similar to Java's BigInteger). Useful if you  needed to compute 
factorial of 1000 exactly.


-- Ron --

1. http://community.computerhistory.org/scc/projects/LISP/book/LISP% 
20I%20Programmers%20Manual.pdf


2. ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-024.pdf

3. http://www-formal.stanford.edu/jmc/history/lisp.ps

4. http://doi.acm.org/10.1145/1086803.1086804

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] The physics of Go playing strength.

2007-04-08 Thread Tom Cooper

Thanks dons for producing these fascinating results.  I hope that
when you have finished the study, you will show us not just this
graph, but also the game results (number of wins) that it is
derived from.

At 02:05 08/04/2007, you wrote:


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


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

2007-04-08 Thread Chrilly
According these results the slope is considerable greater than in chess. In 
the classical experiment of Ken Thompons searching 1 ply deeper is worth 
about 200 Elo. 1 ply corresponds to 5-6 times longer/faster. In 9x9 already 
a factor of 2 gives the same improvement. This is really remarkable. Another 
explanation would be, that 100 Elo have in Go a different meaning than in 
chess.
It is often argued that the distance between week and stronger player is 
much greater in Go than in Chess. In chess the distance between an average 
club player and top humans is about 1000 Elo.
Maybe in Go its 2000 Elo?? In chess the green level-11 version would have 
world-champion level. Is it just enough to make a 2 million playouts version 
to beat the top-Dans in 9x9?  Is it that easy?
Just build a special purpose chip like ChipTest aka Deep Blue. Or implement 
it on a cluster. Or just wait a few years on do it on the PC. Or a 
playstation.


Chrilly



Is there any notion of the Elo rating of a professional Go player. In chess 
terms the
- Original Message - 
From: Don Dailey [EMAIL PROTECTED]

To: computer-go computer-go@computer-go.org
Sent: Sunday, April 08, 2007 3:05 AM
Subject: [computer-go] The physics of Go playing strength.



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 

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

2007-04-08 Thread Tom Cooper
The discussion here http://senseis.xmp.net/?EloRating suggests that 
the difference between beginners and top players in go is about 3000 
ELO on a 19x19 board.  This difference is very dependent on the board 
size.  I can
think of a naive argument that this difference should scale linearly 
with the (linear) size of the board, that is as the square-root of 
the area of the board.


At 08:56 08/04/2007, you wrote:

According these results the slope is considerable greater than in 
chess. In the classical experiment of Ken Thompons searching 1 ply 
deeper is worth about 200 Elo. 1 ply corresponds to 5-6 times 
longer/faster. In 9x9 already a factor of 2 gives the same 
improvement. This is really remarkable. Another explanation would 
be, that 100 Elo have in Go a different meaning than in chess.
It is often argued that the distance between week and stronger 
player is much greater in Go than in Chess. In chess the distance 
between an average club player and top humans is about 1000 Elo.
Maybe in Go its 2000 Elo?? In chess the green level-11 version would 
have world-champion level. Is it just enough to make a 2 million 
playouts version to beat the top-Dans in 9x9?  Is it that easy?
Just build a special purpose chip like ChipTest aka Deep Blue. Or 
implement it on a cluster. Or just wait a few years on do it on the 
PC. Or a playstation.


Chrilly



Is there any notion of the Elo rating of a professional Go player. 
In chess terms the

- Original Message - From: Don Dailey [EMAIL PROTECTED]
To: computer-go computer-go@computer-go.org
Sent: Sunday, April 08, 2007 3:05 AM
Subject: [computer-go] The physics of Go playing strength.



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

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

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 09:56 +0200, Chrilly wrote:
 Is it just enough to make a 2 million playouts version 
 to beat the top-Dans in 9x9?  Is it that easy? 

Of course the ELO numbers are arbitrary.  I assigned GnuGo 3.7.9
a level of 2000 but on CGOS it is 1800.But CGOS numbers are
arbitrary too.   If you can estimate the ELO rating of GnuGo 3.7.9
compared to say a 1 Dan player,  then you can estimate the
winning percentages of any version against a human of a given
strength. 

Mogo of course is about 200-300 higher at the same levels.  So
I believe that if special purpose hardware could bump MoGo up
a few times faster, you would really would have a professional
strength 9x9 player.

It might be easier to do this with a lite play-out version if
you can get substantially more speed, say 4X faster due to
the much simpler move logic.   I don't know hardware, but it
could be easier (more opportunities for parallelism to do it
with a heavy version.)  

- Don


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

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 09:36 +0100, Tom Cooper wrote:
 Thanks dons for producing these fascinating results.  I hope that
 when you have finished the study, you will show us not just this
 graph, but also the game results (number of wins) that it is
 derived from. 

I have all games and all data if anyone want them.   I would probably
build a crosstable of results for each pairing in a final report
on a web page.

- Don


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Re: [computer-go] MoGo

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 11:24 +0200, Heikki Levanto wrote:
  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.   
 
 Weaker players can not estimate the score until very late in the game.
 Not with enough precision, anyway. Thus, most of the time they have no
 idea if they are winning or loosing by 0.5 points. 

But the whole idea is to take you PAST this level of understanding.  

 Then the most obvious
 strategy must be to maximize your score, so that even in case of an
 error in the evaluation or an error in the endgame, the result would
 still be favourable.  

Again, this is probably a good strategy for beginners, but the idea is
to get you beyond this point.   That's why we are talking about a 
program that you can LEARN from.   LEARN means get better.   

So perhaps it is the case that a dumbed down version is better 
initially, but may not help you get past this conceptual barrier.

 This ought to apply to computer programs too, as
 long as we have much uncertainty in the evaluation functions. 

But it doesn't.  I have not seen where maximizing the total won
territory has improved a program.   It's more important to actually
understand what is going on - map out specifically what you need
to win and not worrry about anything else.   You should fight for
the win and this is not a difficult concept - this will make you
much better.

- Don


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

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 14:44 +0200, Heikki Levanto wrote:
 Aren't you being a bit optimistic here? It is quite conceivable that
 the
 curves will flatten out and reach a maximum level somewhat below
 perfect
 play. I don't see how we can predict the difference between them at
 that
 time. 

UCT has been proven to converge to optimum play.  Read some of the
papers.

- Don

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Re: [computer-go] MoGo

2007-04-08 Thread Heikki Levanto
On Sun, Apr 08, 2007 at 08:48:03AM -0400, Don Dailey wrote:
 
 On Sun, 2007-04-08 at 11:24 +0200, Heikki Levanto wrote:
  Weaker players can not estimate the score until very late in the game.
  Not with enough precision, anyway. Thus, most of the time they have no
  idea if they are winning or loosing by 0.5 points. 
 
 But the whole idea is to take you PAST this level of understanding.  

I bet most of the go-playing population (humans and computer programs
alike) are quite incapable of estimating the final score on a 19x19
board except in the yose. Perhaps dan-level amateurs can do it in the
late middle game. But show me the player who can say at move 30 that
playing here will lead to 0.5 point victory, and playing there will
loose the game by a point and a half! Or show me any professional who
claims to know the final score before the tenth move! Such people don't
need to play go, they have already solved the game!


- Heikki


-- 
Heikki Levanto   In Murphy We Turst heikki (at) lsd (dot) dk

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

2007-04-08 Thread compgo123
The question here is not about UCT(yes, it gaves the same rusults as 
alpha-beta). It's about MC scoring. It has not been proved that MC score will 
generate the optimum play with large enough simulation.
 
Now the best super computer uses about 500,000 CPUs, which is 2 to the 18th 
power of computation increase. Don's curve can be tested to the number 18 now.  
 
-Original Message-
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Cc: computer-go@computer-go.org
Sent: Sun, 8 Apr 2007 7:49 AM
Subject: Re: [computer-go] The physics of Go playing strength.


On Sun, 2007-04-08 at 14:44 +0200, Heikki Levanto wrote:
 Aren't you being a bit optimistic here? It is quite conceivable that
 the
 curves will flatten out and reach a maximum level somewhat below
 perfect
 play. I don't see how we can predict the difference between them at
 that
 time. 

UCT has been proven to converge to optimum play.  Read some of the
papers.

- Don

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

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 18:11 +0200, Edward de Grijs wrote:
 Hello Don,
 
 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:
 
 Your work and insight keeps on amazing me.
 
 If I understand is correctly the playouts are made all from the
 root position?
 I am very interested in the results if the larger amount of
 playouts are not made from the root position, but from the
 moment the UCT part is over, and the playouts begin,
 especially with larger amount of playouts.
 I remember some statement of you that it made no
 significant difference if the playouts are multiplied from
 that position, instead of the root position, even with
 hundreds of playouts...
 Do those statements still hold?
 
 Edward de Grijs.

Hi Edward,

Thank you for the kind remarks.

I count the total play-outs - version 0 does 1024 play-outs
period and then the search is stopped cold and a more returned.

It makes the program weaker if you just do N play-outs from the
leaf position of UCT.   But it does not seem to hurt the program
at all to not expand the existing CHILDREN of a node, until the
parent has been visited, say 100 times.   I have not tried anything
larger than 100, but if it's weaker with 100, I haven't been able
to measure it.This really is huge benefit in memory usage,
so I like 100.   Of course this means some children will get 2 or 
more visits before getting expanded.There is no need for 
this if you have memory to burn.  

I'm not sure what experiment you are proposing, but at some
point it might be interesting to see how other values work.
If you have a computer with very little memory to spare, you
could probably use much larger numbers although at some point
you would surely experience a noticable weakening.

If you are proposing doing 2, 3, 4 or more play-outs at the
point where you normally do one,  I think it strengthens the
program - but not enough to justfy the extra work.   In other
words doing 2 play-outs doubles the amount of time spent on
a move and it does not increase the strength enough to 
justify this.


- Don






 
 
 
 From: Don Dailey [EMAIL PROTECTED]
 Reply-To: [EMAIL PROTECTED], computer-go computer-go@computer-go.org
 To: computer-go computer-go@computer-go.org
 Subject: [computer-go] The physics of Go playing strength.
 Date: Sat, 07 Apr 2007 21:05:19 -0400
 
 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.)

Re: [computer-go] MoGo

2007-04-08 Thread Don Dailey
I'm not really fanatic about this either way.  If I knew how to 
easily fix this, I probably would provide a mode to make it
work either way.

I see it as aesthetically MORE pleasing when the program appears
to be playing stupid, but then you realize that YOU are the one
that doesn't understand.   

When I first started studying chess as a little boy, I was
completely annoyed that the grandmasters never played the game
out but resigned.   I realize now that it is not aesthetically
pleasing to pretend you don't realize the game is over.

I feel this way a little bit here (but not enough to lose any
sleep over.)   It's almost ugly (to me) for it to pretend to
fight for something that doesn't matter - almost childishly.

But of course I agree that from a stylistic point of view you
can see the cleanup phase as just a continuation of good habit.

- Don


On Sun, 2007-04-08 at 11:02 -0600, Arend Bayer wrote:
 
 
 On 4/7/07, Don Dailey [EMAIL PROTECTED] wrote:
 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.
 
 I am mostly with Matt on this one. Take endgame: If you only ever
 fight for every point in the endgame when it actually matters, then
 you get very few opportunities to learn a precise endgame. 0.5 leads
 before the endgame are just extremely rare unless the players are at
 professional level. Also, in a typical 19x19 endgame, when you are
 down by 3 points and playing against an amateur, your best chance is
 just to fight for every single point and hope your opponent makes 2-3
 small slips that add up to 3-4 points. I.e. in a realistic game,
 maximizing your winning percentage is often equivalent to just playing
 for a small loss for now; so the UCT all-or-nothing approach is just
 almost never the right thing to do for humans (unless the position is
 truly hopeless). 
 
 There are also aesthetical reasons why I prefer professional handling
 of lost games over UCT's, but that's another email.
 
 Arend
 
 
 

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

2007-04-08 Thread Don Dailey
On Sun, 2007-04-08 at 10:09 -0400, [EMAIL PROTECTED] wrote:
 The question here is not about UCT(yes, it gaves the same rusults as
 alpha-beta). It's about MC scoring. It has not been proved that MC
 score will generate the optimum play with large enough simulation.   

MC is obviously wrong as an evaluation function - it is not guaranteed
to
return a correct or even a good score no matter how many simulations.

However, UCT eventually turns into a pure tree where MC is not 
a factor.These programs, in theory, will play perfect GO given 
enough time.


- Don


 Now the best super computer uses about 500,000 CPUs, which is 2 to the
 18th power of computation increase. Don's curve can be tested to the
 number 18 now.

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[computer-go] CGOS

2007-04-08 Thread Don Dailey
Just a warning - 

Tomorrow, I'm taking the old CGOS down and replacing it with
the NEW cgos.  

Also, the CGOS test I'm running from my home computer will
go away.   So the 2 minute server will also go away!

The new cgos on boardspace will be 5 minute time control
instead of the previous 10 minute.

I will save the games on the 2 minute server for a few weeks,
so if anyone wants them for any reason - let me know ASAP,
because I probably won't keep them around forever.   

I will archive the games of the old CGOS but I will be taking
them off the boardspace server to make room for the new server.

If anyone has space and would like to archive all the old CGOS
games, let me know.   Otherwise, I will keep them for a year
or two (longer if it's convenient) and they will be avaiable 
by request.

I've also improved the viewing client a bit.  I will make all
this available tomorrow.

- Don


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

2007-04-08 Thread compgo123
I think you are right, because MC score becomes precise when only a few 
available moves left. However, do you search to the depth of the end of the 
game, or to the extent that MC score becomes precise?
 
 
-Original Message-
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Cc: computer-go@computer-go.org
Sent: Sun, 8 Apr 2007 2:22 PM
Subject: Re: [computer-go] The physics of Go playing strength.


On Sun, 2007-04-08 at 10:09 -0400, [EMAIL PROTECTED] wrote:
 The question here is not about UCT(yes, it gaves the same rusults as
 alpha-beta). It's about MC scoring. It has not been proved that MC
 score will generate the optimum play with large enough simulation.   

MC is obviously wrong as an evaluation function - it is not guaranteed
to
return a correct or even a good score no matter how many simulations.

However, UCT eventually turns into a pure tree where MC is not 
a factor.These programs, in theory, will play perfect GO given 
enough time.


- Don


 Now the best super computer uses about 500,000 CPUs, which is 2 to the
 18th power of computation increase. Don's curve can be tested to the
 number 18 now.

AOL now offers free email to everyone.  Find out more about what's free from 
AOL at AOL.com.
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Re: [computer-go] The dominance of search (Suzie v. GnuGo)

2007-04-08 Thread Jacques Basaldúa

Don Dailey wrote:


I have this idea that perhaps a good evaluation function could
replace the play-out portion of the UCT programs.


I thought about something similar but only for initializing the 
counters: introduce 10 fake playouts and estimate the number of
wins by a function returning something in [0, 10]. After that, 
use UCT with real playouts.


If your guess was right, that should improve performance, but if
it was wrong you are doing nothing irreversible except loosing 
time.



Jacques.


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

2007-04-08 Thread Chris Fant

 I have this idea that perhaps a good evaluation function could
 replace the play-out portion of the UCT programs.

I thought about something similar but only for initializing the
counters: introduce 10 fake playouts and estimate the number of
wins by a function returning something in [0, 10]. After that,
use UCT with real playouts.

If your guess was right, that should improve performance, but if
it was wrong you are doing nothing irreversible except loosing
time.


Another option is to replace the playout by a partial playout followed
by a static evaluation, which would probably be deterministic (that's
acceptable since the partial playout introduced plenty of
non-determinism).
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Re: [computer-go] Simplified MC evaluator ¿explained?

2007-04-08 Thread Martin Møller Pedersen

On 08/04/07, Jacques Basaldúa [EMAIL PROTECTED] wrote:

I will try to explain it better:

What had puzzled me until recently is how to combine two facts:

 a. As Jason says,  A single MC playout corresponds to a Bernoulli
trial with probability p and therefore, p-hat is distributed as a binomial
which converges to the normal.


See also:
http://en.wikipedia.org/wiki/Bernoulli_process

Regards
Martin
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