It is currently Thu Mar 28, 2024 2:52 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 122 posts ]  Go to page 1, 2, 3, 4, 5 ... 7  Next
Author Message
Offline
 Post subject: The Probability of a Monkey Defeating Yi Chang-ho
Post #1 Posted: Fri Aug 17, 2012 2:57 am 
Gosei
User avatar

Posts: 1581
Location: Hong Kong
Liked others: 54
Was liked: 544
GD Posts: 1292
http://tchan001.wordpress.com/2012/08/1 ... -in-a-tie/
Read the second part of this post on a new Chinese go book :) enjoy

_________________
http://tchan001.wordpress.com
A blog on Asian go books, go sightings, and interesting tidbits
Go is such a beautiful game.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #2 Posted: Fri Aug 17, 2012 5:07 am 
Gosei
User avatar

Posts: 2116
Location: Silicon Valley
Liked others: 152
Was liked: 330
Rank: 2d AGA
GD Posts: 1193
KGS: lavalamp
Tygem: imapenguin
IGS: lavalamp
OGS: daniel_the_smith
I think actual random play is more like 50k or 150k than 20k. But still an amusing piece.

_________________
That which can be destroyed by the truth should be.
--
My (sadly neglected, but not forgotten) project: http://dailyjoseki.com

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #3 Posted: Fri Aug 17, 2012 5:21 am 
Gosei
User avatar

Posts: 1581
Location: Hong Kong
Liked others: 54
Was liked: 544
GD Posts: 1292
But the monkey isn't just playing randomly, he's playing random moves which are legal moves.

_________________
http://tchan001.wordpress.com
A blog on Asian go books, go sightings, and interesting tidbits
Go is such a beautiful game.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #4 Posted: Fri Aug 17, 2012 6:04 am 
Tengen
User avatar

Posts: 4511
Location: Chatteris, UK
Liked others: 1589
Was liked: 656
Rank: Nebulous
GD Posts: 918
KGS: topazg
tchan001 wrote:
But the monkey isn't just playing randomly, he's playing random moves which are legal moves.


Even within legal moves, I'd also estimate randomly is at best 50k

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #5 Posted: Fri Aug 17, 2012 6:15 am 
Tengen

Posts: 4380
Location: North Carolina
Liked others: 499
Was liked: 733
Rank: AGA 3k
GD Posts: 65
OGS: Hyperpape 4k
Absolute beginners really are almost 30k on KGS, and they're playing only legal moves, most of which are better than random.

_________________
Occupy Babel!

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #6 Posted: Fri Aug 17, 2012 6:20 am 
Gosei
User avatar

Posts: 1581
Location: Hong Kong
Liked others: 54
Was liked: 544
GD Posts: 1292
Is there actually a way to play illegal moves on KGS?

Regardless of whether the monkey is 21k or 50k, the point is P1 is a very very small probability but will still be much bigger than P0 and the rest of the arguments will still be very usable.

Anyways, I'm not the author of the piece. I'm only presenting it in English to the Western audience ;)

_________________
http://tchan001.wordpress.com
A blog on Asian go books, go sightings, and interesting tidbits
Go is such a beautiful game.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #7 Posted: Fri Aug 17, 2012 6:38 am 
Tengen
User avatar

Posts: 4511
Location: Chatteris, UK
Liked others: 1589
Was liked: 656
Rank: Nebulous
GD Posts: 918
KGS: topazg
hyperpape wrote:
Absolute beginners really are almost 30k on KGS, and they're playing only legal moves, most of which are better than random.


I've played a lot of absolute beginners, and they don't compare to idiotbot for badness, even when they're playing their first game having had the rules just explained to them.


This post by topazg was liked by: Bonobo
Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #8 Posted: Fri Aug 17, 2012 7:19 am 
Gosei
User avatar

Posts: 2011
Location: Groningen, NL
Liked others: 202
Was liked: 1087
Rank: Dutch 4D
GD Posts: 645
Universal go server handle: herminator
A "random legal move monkey" is not stronger than 300k

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #9 Posted: Fri Aug 17, 2012 7:58 am 
Lives in sente
User avatar

Posts: 761
Liked others: 152
Was liked: 204
Rank: the k-word
If you accept the assumptions given in the article about the relative strength between ranks, then P0 corresponds to a rank of 330 kyu.

The actual strength of a random player is probably much lower than even that (what would stop it from killing all of its living groups?)

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #10 Posted: Fri Aug 17, 2012 8:04 am 
Gosei
User avatar

Posts: 2011
Location: Groningen, NL
Liked others: 202
Was liked: 1087
Rank: Dutch 4D
GD Posts: 645
Universal go server handle: herminator
palapiku wrote:
(what would stop it from killing all of its living groups?)


Presumably there is a chance that it will pass in a situation where white has no legal moves and must also pass, so the game is then counted?

E.g Suppose I give it 280 handicap, putting a black stone on every coordinate where either the row or the column is odd (so only the point that have both coordinates even remain open). If it passes before filling 80 of its 81 eyes, it then wins.


This post by HermanHiddema was liked by: Joaz Banbeck
Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #11 Posted: Fri Aug 17, 2012 8:25 am 
Lives in sente
User avatar

Posts: 761
Liked others: 152
Was liked: 204
Rank: the k-word
That's a good point... I didn't think of the actual logistics of playing with huge handicap :)

Of course, the assumption in the article is wrong anyway - the probability of losing to someone one stone weaker is not a static 25%. It actually approaches 50% as strength of the players declines, i.e. komi becomes less of a factor. (This happens because variance of final scores increases. High dans often end games within a few points of each other. A game between two nearly-random players could easily finish with a difference of thousands of points).

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #12 Posted: Fri Aug 17, 2012 8:32 am 
Tengen

Posts: 4380
Location: North Carolina
Liked others: 499
Was liked: 733
Rank: AGA 3k
GD Posts: 65
OGS: Hyperpape 4k
topazg wrote:
hyperpape wrote:
Absolute beginners really are almost 30k on KGS, and they're playing only legal moves, most of which are better than random.


I've played a lot of absolute beginners, and they don't compare to idiotbot for badness, even when they're playing their first game having had the rules just explained to them.
And idiotbot isn't really 30k. People resign against it: http://eidogo.com/#url:http://files.gok ... t-Brau.sgf.

_________________
Occupy Babel!

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #13 Posted: Fri Aug 17, 2012 9:35 am 
Lives with ko
User avatar

Posts: 202
Location: Raleigh, NC
Liked others: 94
Was liked: 53
Rank: AGA 2 dan
GD Posts: 54
I think the most interesting part of this article is the attempt to show the gap between ranks mathematically. A simple range of numbers like this really puts the difficulty of rising to the top into perspective. Much more than the (x books to 1k, y books to shodan, z books to 2dan, ect…) theory which doesn’t seem to have any basis whatsoever.

_________________
Ko is the best solution.
With Ko, I can keep eating and drinking until I am full.

Visit >>>Koosh's Study Journal<<<

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #14 Posted: Fri Aug 17, 2012 10:20 am 
Honinbo

Posts: 10905
Liked others: 3651
Was liked: 3374
OK. Random Monkey sees eight legal moves on the board, and he also has a pass move available. He has four live groups, each with two single point eyes. Eight to one Random Monkey fills an eye. :mrgreen:

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #15 Posted: Fri Aug 17, 2012 11:59 am 
Beginner

Posts: 14
Liked others: 39
Was liked: 0
We can assume Random But Not Stupid Monkey who will pass if and only if all legal moves fill an eye.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #16 Posted: Fri Aug 17, 2012 12:03 pm 
Lives in sente

Posts: 800
Liked others: 141
Was liked: 123
Rank: AGA 2kyu
Universal go server handle: speedchase
Txewì wrote:
We can assume Random But Not Stupid Monkey who will pass if and only if all legal moves fill an eye.

No we can't, it will decide at random. otherwise it isn't a random monkey, it is a almost random monkey.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #17 Posted: Fri Aug 17, 2012 12:50 pm 
Beginner

Posts: 14
Liked others: 39
Was liked: 0
speedchase wrote:
Txewì wrote:
We can assume Random But Not Stupid Monkey who will pass if and only if all legal moves fill an eye.

No we can't, it will decide at random. otherwise it isn't a random monkey, it is a almost random monkey.

That's like saying it's only random if it can play illegal moves, or if it can play between the points, or if it can fling mud instead of playing, or ...

We constrain the monkey to play legal moves because otherwise it isn't go. If we don't also relieve it of the obligation to eventually make all of its groups killable, it's not Random Monkey, it's Loses Every Game Monkey, about whom nothing interesting can really be said.

Edited to add: actually, Resigns On Its First Move Monkey would have a rating of ∞ kyu (since it wins 50% of games against itself and 0% of games against everyone else), which is somewhat interesting.

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #18 Posted: Fri Aug 17, 2012 1:41 pm 
Lives in sente

Posts: 800
Liked others: 141
Was liked: 123
Rank: AGA 2kyu
Universal go server handle: speedchase
It could still win 50% of the games if handicapped well. if you starting making it do things besides just following the rules, it is no longer random

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #19 Posted: Fri Aug 17, 2012 1:44 pm 
Lives in sente
User avatar

Posts: 761
Liked others: 152
Was liked: 204
Rank: the k-word
Of course the game has to end at some point so the random monkey needs to be able to pass. So what should the probability of passing be? 1/361?

Top
 Profile  
 
Offline
 Post subject: Re: The Probability of a Monkey Defeating Yi Chang-ho
Post #20 Posted: Fri Aug 17, 2012 1:55 pm 
Dies with sente

Posts: 87
Location: Munich, Germany
Liked others: 341
Was liked: 17
Rank: EGF 5kyu
palapiku wrote:
Of course the game has to end at some point so the random monkey needs to be able to pass. So what should the probability of passing be? 1/361?


First idea: If there are N legal moves on the board, each one and the passing move should have probability 1/(N+1).
Second: As passing is actually a mere expression of "I think we're done", the monkey is not allowed to pass, but Yi Chang-ho says when to stop the game.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 122 posts ]  Go to page 1, 2, 3, 4, 5 ... 7  Next

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot] and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group