Re: [computer-go] Life and Death

2008-03-27 Thread Tom Cooper

I think that the original description of the position should have said
'killable' rather than 'dead', and that David missed the fact that
it is White to move.

At 08:06 27/03/2008, Hideki wrote:


David Fotland: [EMAIL PROTECTED]:
I just looked at this position and it looks like a win for black in the
first position.  Many Faces evaluates it as a win for black, and plays c1 to
save the lower left black group with almost no thinking time.

Mogo is correct because the lower left black group is not dead.

I'm sorry if wrong but the black seems dead by B5 after C1, isn't
it?

-Hideki

David

 -Original Message-
 From: [EMAIL PROTECTED] [mailto:computer-go-
 [EMAIL PROTECTED] On Behalf Of Matthew Woodcraft
 Sent: Sunday, March 09, 2008 11:49 AM
 To: computer-go
 Subject: [computer-go] Life and Death

 I've included two 13x13 positions below. In both positions it is
 Black's
 move.

 The first position is simplified from a real game. Black has two
 enclosed dead groups, and White has a small but easy win.

 The second position is a modified version of the first in which the
 dead
 groups are more obviously dead.

 If I try MogoRelease3 playing as Black on position 2, it shows a 20%
 score and resigns either immediately or after a couple of moves.

 If I try it on position 1, it shows a score of 70%+ for Black, and
 continues to play until White takes steps to remove the dead groups
 from
 the board. I've tested with up to 2^24 playouts.

 I have tried increasing --collectorLimitTreeSize and --limitTreeSize
 (like bigMogo in the scalability study), but I can't set them much
 higher than the default on this machine without running out of memory.

 I'd be interested to see if someone with a bigger computer can find out
 what resources it needs to judge this position well, and to see how
 other engines do.

 Position 1

 (;GM[1]FF[4]
 CA[UTF-8]
 SZ[13]
 HA[0]
 KM[0.5]
 AB[jb:kb][cb:cc][kc][bd:cd][jd:ld][be][he][cf:df][bg][gb:gh]
 [ig:ih][jh:kh][eg:ei][li][aj:bj][hi:hj][lk][al][ck:cl][ji:jl]
 [dm][im]
 AW[ia:ja][ib][hc:jc][db:dd][hd:id][ce:de][ie][ke:le][bf][hf:jf]
 [lf][jg:kg][mg][lh][ai:di][gi][mi][cj][ej:gj][ij][dk:fk][hk:ik]
 [dl][il][bm][fl:fm][hm]
 )

 Position 2

 (;GM[1]FF[4]
 CA[UTF-8]
 SZ[13]
 HA[0]
 KM[0.5]
 AB[jb:mb][cb:cc][kc][bd:cd][jd:md][be][he][cf:df][bg][gb:gh]
 [ig:ih][jh:kh][eg:ei][li][aj:bj][hi:hj][bk:ck][lk][al][cl]
 [ji:jl][im]
 AW[ia:la][ib][hc:jc][mc][db:dd][hd:id][ce:de][ie][ke:le][bf]
 [hf:jf][lf][jg:kg][mg][lh][ai:di][gi][mi][cj][ej:gj][ij][dk:fk]
 [hk:ik][dl][fl][il][bm:cm][em:fm][hm]
 )

 -M-
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Re: [computer-go] New scalability study progress report

2008-01-20 Thread Tom Cooper

This is very cool.  As of 261 games played, I find it very difficult to
guess whether the mogo curve is beginning to dramatically flatten, or
will continue to rise steeply.

I have a few questions.

I can't see the cross table, I guess you haven't put it up yet?

How do you decide the pairings?  I think more even pairings would be
more informative, and lead to faster convergence, but I suppose you
don't just want bots playing adjacent bots?

Are you going to ask for volunteers to run this script?  I think it
is more likely to give interesting results than the SETI thing.

At 01:31 19/01/2008, Don wrote:


The new scalability study is in progress.  It will be very slow going,
only a few games a day can be played but we are trying to get more
computers utilized.

I will update the data a few times a day for all to see.   This includes
a crosstable and ratings graphs.   The games will be made available for
anyone who wants them.

Although it's not on the graph itself,  Gnugo-3.7.11 level 10 is set to
be 1800.0 ELO.The bayeselo program is used to calculate ratings.

Results can be found here:

http://cgos.boardspace.net/study/index.html

bayeslo assumes all players are equal strength until significant
evidence proves otherwise,  and with only a few games played each,  the
graph will look truly strange, but this will correct itself in time.

Each data point in the x axis represent a doubling in power.   There are
13 doublings represented and mogo was set to approximate FatMan in
strength at each point - at least at the lower level but only with a
very crude and rough estimate. Since I don't know how well mogo
scales compared to FatMan, we can only wait and see how this works out
at the top levels.

- Don

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Re: [computer-go] U. of Alberta bots vs. the Poker pros

2007-07-28 Thread Tom Cooper

At 02:58 28/07/2007, Arend wrote:



On 7/26/07, chrilly 
mailto:[EMAIL PROTECTED][EMAIL PROTECTED] wrote:

This is a remarkable result. I think poker is more difficult than Go and of
course chess.


I am as surprised by this statement as everyone else. Of course you 
have to develop some mixed strategies, try go guess implied pot 
odds, folding equity etc. but assuming you have access to a large 
database of high level poker games to analyze, why should it be that 
hard, esp. in 2-person limit Hold'em?


Arend



It seems plausible to me that poker should, in some sense, be more 
complicated than go.  I'll ignore the massive savings from clever 
search tricks in both games.  In order to get optimal play in go, it 
is necessary to search over all legal positions, of which there are 
fewer than 3^(19^2).  In order to get optimal play (ie a Nash 
equilibrium) in poker, it is necessary to search over all strategies 
(of both players).  A strategy is a map from your knowledge (the 
cards you can see and the opponent's bids) to an action.  Even if we 
assume a single round of bidding, the number of strategies for a 
single player is roughly (no. of actions)^(no.hands * no opponents 
bids).  This is massively higher than the number of go positions. 


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[computer-go] OT U. of Alberta bots vs. the Poker pros

2007-07-28 Thread Tom Cooper

At 18:20 26/07/2007, Jeff Nowakowski  wrote:


On Thu, 2007-07-26 at 18:14 +0200, chrilly wrote:
 Chess/Go... can be played in an autistic way. There is no need for an
 opponent model.

Ah, an opponent model.  Where's the poision?

http://www.imdb.com/title/tt0093779/quotes#qt0250635

Too much rock, paper, scissors in poker for my tastes.  Can there ever
be a best player?  At least in Go the differences in strength are very
clear, and some guy off the street who learned the game a year ago is
not going to win a tournament.

-Jeff




Rock,paper,scissors, also known as Roshambo is not an interesting game in my
opinion (except perhaps for the human psychology involved).  Because of the
symmetry between the strategies, it is clear that objectively speaking, all
strategies are equally good, even for multi-round games.  There is a 
single optimal

mixed strategy which chooses a move at random from a distribution for which
each play has probability 1/3.

However, if you break that symmetry, say by adding a 1/100 of a round 
bonus every
time a player chooses rock, the game becomes more interesting, though 
it is still

possible to find the optimal mixed strategy in a few lines of calculation.

Any variety of poker is sufficiently complicated that it is very difficult to
find an optimal mixed strategy, and therefore it is, as far as my 
interest in it
is concerned, very different from Roshambo.  Perhaps it is true 
though that even

with an optimal strategy, the 'noise' on ones winnings would be so high that
one wouldn't stand out from the crowd. 


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Re: [computer-go] U. of Alberta bots vs. the Poker pros

2007-07-28 Thread Tom Cooper

At 12:42 28/07/2007, you wrote:

At 02:58 28/07/2007, Arend wrote:



On 7/26/07, chrilly 
mailto:[EMAIL PROTECTED][EMAIL PROTECTED] wrote:

This is a remarkable result. I think poker is more difficult than Go and of
course chess.


I am as surprised by this statement as everyone else. Of course you 
have to develop some mixed strategies, try go guess implied pot 
odds, folding equity etc. but assuming you have access to a large 
database of high level poker games to analyze, why should it be 
that hard, esp. in 2-person limit Hold'em?


Arend



It seems plausible to me that poker should, in some sense, be more 
complicated than go.  I'll ignore the massive savings from clever 
search tricks in both games.  In order to get optimal play in go, it 
is necessary to search over all legal positions, of which there are 
fewer than 3^(19^2).  In order to get optimal play (ie a Nash 
equilibrium) in poker, it is necessary to search over all strategies 
(of both players).  A strategy is a map from your knowledge (the 
cards you can see and the opponent's bids) to an action.  Even if we 
assume a single round of bidding, the number of strategies for a 
single player is roughly (no. of actions)^(no.hands * no opponents 
bids).  This is massively higher than the number of go positions.

___



Sorry, this isn't what I meant to say.  A sensible strategy in poker 
has to involve bluffing, so it is a map from knowledge into 
distributions over actions.  The point about it's being bigger than 
the space for go is right though. 


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Re: [computer-go] 9x9 games wanted and the next big challenge

2007-07-09 Thread Tom Cooper
Yes.  This number is strongly dependent on strength and board size I 
think.  Very roughly speaking, you can argue as follows
1) in a 9x9 game, the weaker player has only 1/4 as many moves in 
which to throw away the handicap advantage (compared to 19x19).
2) weak players lose so many points compared to perfect play that the 
final score (the difference between the number of points the two 
players lose) has a large variance compared to the value of a handicap stone.




According to some early experiments I have made on a database of 
games played by humans on KGS, I'd say it is more likely to be 70 or 
80 Elo points. Also, it is likely to depend on strength. I'll be 
able to give more precise data in a few weeks.


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Re: [computer-go] creating a random position

2007-07-08 Thread Tom Cooper

At 21:54 08/07/2007, you wrote:

I don't have  such algorithm,  you can count legal positions like: 
http://www.lysator.liu.se/~gunnar/legal.pike.txt


Modifying it could provide some way select random position atleast 
for small boards. Ported that for java but not studied much of it 
yet, intresting anyway.


t. Harri



This page seems more up to date, and links a paper 
http://homepages.cwi.nl/~tromp/go/legal.html 


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Re: [computer-go] Re: 9x9 games wanted

2007-07-06 Thread Tom Cooper
It might be worth asking the administrators of some go servers if 
they would be prepared to give you copies of some games.


At 17:09 06/07/2007, you wrote:

I will play with Suzie at the forthcoming European Go championship 
in Villach/Austria some 9x9 demonstration matches against everybody 
who wants to play.
I want to prepare an opening book and I am looking for a 9x9 games 
collection. So far I have only found in total 244 games, which is 
for a book much too less (I am used to have the CB-Megabase).

Is there a larger collection with at least = 5 Amateur Dan Level available?
If the price is reasonable, I am willing to pay for a professionally 
made collection.


Chrilly
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[computer-go] article in the Times

2007-06-30 Thread Tom Cooper

It isn't a very good article in my opinion, but for what it's worth.

http://www.timesonline.co.uk/tol/comment/columnists/ben_macintyre/article2002699.ece

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RE: [computer-go] Sylvain's results

2007-04-12 Thread Tom Cooper

There are multiple possible definitions of what it means for a player
to be the same strength on two different sized boards.  It is impossible
to pit a 9x9 player against a 19x19 player.  If two people
use different definitions of 'same strength', they are bound to disagree
about which size people are better at.

Off the top of my head, 'same strength'could be defined as
i) Same amount of experience of both games,
ii) Drops the same number of points over the course of the game
   when playing a perfect player,
iii) As ii), but scaled for the board area,
iv) Typically reads the same number of moves,
v) Same win rate on average when playing typical human players,
vi) Same win rate on average when playing Gnu Go.

At 05:42 12/04/2007, you wrote:


On Wed, 2007-04-11 at 17:29 -0700, David Fotland wrote:
 No, humans are much weaker on 9x9 than on 19x19.

David,

I saw this on Sensei's Library that indicates larger boards
are harder:

[ snip ]

  In [ext]The Theory  Practice of Go, Korschelt describes an
experimental 21x21 goban that he constructed and turned over to his
Master, Murase Shuho, for testing. He describes a sample game that was
played out to about 130 moves before ending. Only the first 57 were
shown.

Korschelt remarked that the game took on a freer and more deeply
involved character, but ... at the same time the difficulty of keeping
command of the game grew at an extraordinary rate. He goes on to note
that on a 19x19 board, too many unexpected situations turn up for
beginners, and speculates that if the board were to increase to 23x23,
not even the best players could any longer maintain a comprehensive
view of the countless possible combinations.

[ snip ]

This seems to also match my intuition, even though I'm not as good a
player as you are.   If you extrapolate backwards, to 7x7, 5x5, 3x3
it seems clear that smaller boards are less complex and therefore
easier to master.   I cannot believe 9x9 is harder than 19x19 and
I don't care how strong the player is who says that - I don't believe
it.

- Don


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

2007-04-11 Thread Tom Cooper

Thank you Sylvain for conducting these experiments.  We have had some very
enlightening results posted here recently in my opinion.  I have to admit,
I'm surprised at how well the program seems to scale.  Fortunately, I didn't
make a bet. :)

Taking for granted that these results indeed show what they seem to, and
combining them with the success of Monte-Carlo methods on 7x7 and 9x9 boards,
I'll have to change my opinion about the future of computer go quite radically.

It now seems believable to me that computer go will go the way of 
computer chess,

and within the next decade or so as well.  Or maybe Chrilly will make a monster
go machine even before that.

Could somebody comment please on the likely usefulness of massively parallel
machines to UCT-like algorithms.

Thanks again.
Tom.

At 21:12 10/04/2007, you wrote:


Hello,

2007/4/6, Tom Cooper 
mailto:[EMAIL PROTECTED][EMAIL PROTECTED]:

My guess is that the complexity of achieving a fixed standard of play
(eg 1 dan) using a global alpha-beta or MC search is an exponential
function of the board size.


(...)
To some extent, this is testable today by finding how a global search
program's strength scales with board size and with thinking
time


I have experiments of MoGo's playing strength against a fixed player 
(Gnugo 3.7.10 level 8) on different board sizes and different thinking times.
Of course, to meet your statement we have here to assume that the 
level of gnugo level 8 is a constant with the board size.


The results are that in order to keep the same winning rate, you 
have to increase the number of simulations by something a little 
larger than linear in the board area. From 9x9 to 13x13, you need 
something like 3 times more simulations for the same winning rate. 
Same thing from 13x13 to 19x19. As the time of one simulation is 
linear in the board area, to keep the same level you have to give a 
time which increases as power ~2.5 of the board area. So between 9x9 
and 19x19, you have to give 32x more time per move for the same 
play level (always defined as winning rate against gnugo).
This is far from being exponential. (maybe if it was exponential, 
there would be little interest to work on 9x9 go).


Sylvain
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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 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 dominance of search (Suzie v. GnuGo)

2007-04-06 Thread Tom Cooper
My guess is that the complexity of achieving a fixed standard of play 
(eg 1 dan) using a global alpha-beta or MC search is an exponential 
function of the board size.  For this guess, I exclude algorithms 
that have a tactical or local component.  If this guess is correct 
then, even if Moore's law remains in force, this kind of program 
should not reach dan level on a 19x19 board within 20 years.


To some extent, this is testable today by finding how a global search 
program's strength scales with board size and with thinking 
time.  For example, results in which Suzie had a week to play a 13x13 
game would be interesting.


I don't mean to imply by this message that I think I am particularly 
well qualified to have an opinion on this matter, but when someone 
writes something that surprises me, I'm inclined to argue :)





On 13x13 and especially 19x19 Suzie is still weaker than Gnu-Go. I 
think the hardware is still too weak to establish the same dominance 
of search for larger board-sizes. But thats only a matter of time or 
of a few million $ to build (with Chris Fant) a Go-Chip. Actually 
about 100.000 Euro for an FPGA based project would be sufficient.


Chrilly Donninger



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Re: [computer-go] computer go documentation issues

2007-03-22 Thread Tom Cooper

I agree.  The feel of sensei's and wikipedia are completely different.
Most of the content on sensei's is too informal for wikipedia, and I
think it would get deleted if it was put there, despite this content
being very worthwhile.  On the other hand,
wikipedia is the ideal place for a short authoritative introduction.

At 13:25 19/03/2007, dons wrote:


Sensei and Wikipedia serve somewhat different purposes and I
believe they should both be kept up to date.

I don't believe the detail of Sensei's Library should be
covered by Wikipedia.   If I first wanted to get acquainted
with some subject I might look it up in an encyclopedia to
get an overview, then I would look for more detailed information
in a book or other publications.   I think this is how the
two should work together.

- Don


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Re: [computer-go] Useless moves in the endgame

2007-01-10 Thread Tom Cooper

At 16:20 09/01/2007, you wrote:


i'd like to follow this up by saying that i'm interested
to see if anyone has compared winning percentage
in the following two situations:

i)  maximize probability of win
ii) maximize probability of win until p_win  1-eps, then maximize
total score among all moves that give  1-eps probability of winning.

if ii) gives a lower percentage of wins than i), it'd be an interesting
result in its own right, and if it doesn't, then there's a simple formula
for getting a lot more resignations out of your opponents (not to
mention, it'll give the impression that your program is incredibly strong
whenever it wins).



To me it seems sensible to maximize a different measure.  I would be interested
to know how the following scheme performs.

Choose the starting move which maximizes [sum (s(n)+k*w(n))]/N,
where N is the number of games with this starting move,
n takes the values 1...N: the sum is over these values,
k is a non-negative constant,
s(n)is the net score of the bot (eg the bot's area minus its opponent's 
area) in game n, and

w(n) is 1 if the bot wins game n and 0 if it loses.

When k is very large, this scheme should essentially just count the wins, like
traditional monte-carlo.  Smaller values of k will encourage the bot to try
to accumulate more points unless that makes a significant difference to the
winning percentage.

A value of k around 300 might be a sensible value.  The computer might then 
trade

a 30 point group for a 1% chance of winning.

I suspect that this scheme will still reduce the bot's winning percentage, 
but that there

might be a value of k that will improve the 'look' of the bot's play while only
making a negligible difference to the winning percentage.

When working out s(n), it makes no difference to the play if komi is taken 
into account,

as long as a consistent method of evaluating the score is used.

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Re: [computer-go] Re: Interesting problem

2007-01-04 Thread Tom Cooper

At 23:17 03/01/2007, Don wrote:


David,

I thought of another way to put it which I think, in a way,
defines the difference in the rule-sets.

You are playing a game, and you think the opponent group
is dead.  But you are not 100 percent sure.

What do you do?  Chinese puts the emphasis on the actual
truth of the situation.   Japanese makes you gamble, and
penalizes you for being wrong.   It makes your opinion
about the situation become a factor in the final result
instead of the board position and your play leading up
to it.


Don, I can see that chinese rules let a player try a speculative
invasion inside his opponents territory at the end of the game
without risk, but you seem to be saying more than this.  Could
you give a 5x5 example or two please?  I had heard that in some
sense, chinese rules require more sophisticated understanding
for perfect play.

It might be best to construct
the example by playing a pretend game so that each player has
played the fair number of stones.

Thanks 


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Re: [computer-go] When is Pass the best move?

2006-10-23 Thread Tom Cooper

At 01:54 23/10/2006, you wrote:

There was a posting on this list with an example of a (contrived?) 
situation where sacrificing a pass-alive group is appropriate, in order to 
win a ko that is more valuable.  Is even #1 100% admissible?


Weston



I must have missed this, and find it surprising.  Can anyone remember the 
example?




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