Re: computer-go: Winning strategy speculation and loosing games.

["Magnus Persson" <magnus.persson@xxxxxxxxxx>]

> Some recent comments made me wonder if anyone has tried to make "worst"
> go program. The task is not so obvious...It could probably be usefull in
> some way to help make good go programs. Maybe someone even tried to make
> a tournement of such bad go programs? 
> 
> Yannick Delbecque

To save time I dug up something I wrote on this list some years ago. 
The idea here is that a random player that do not fill in eyes is the 
simplest program that do not lose all games it plays. If a program is 
not allowed to fill its own eyes it maybe takes more "Go knowledge" 
to play even worse... it becomes a new game where the winner is the 
"loser" in normal go. 

Playing the random player with high handicaps are far from easy and 
require new strategies as noted below. 


> From:           	"Magnus Persson" <magnus.persson@xxxxxxxxxxxxxxxxx>
> To:             	computer-go@xxxxxxxxxxxxxxxxx
> Date sent:      	Mon, 31 Aug 1998 13:52:14 +0000
> Subject:        	Judging programs from one example and random play
> Send reply to:  	magnus.persson@xxxxxxxxxxxxxxxxx Priority:       	normal
> 
> 
> > Darren Cook wrote:
> > 
> > Kojima 9-dan did a commentary of the Many Faces/Young Leaf game and
> > said he was very impressed with the way it ('it' being young leaf I
> > think) made a group live. Something about he didn't think computers
> > could make such good moves.
> 
> Just some randoms thoughts that are not so relevant, but I could not
> stop writing after i started:
> 
> It is probably too easy to make too positive conclusions 
> from just one case in each game. I think one should expect any 
> computer program  to make at least one strong move  in each game.
> 
> As an example I once made a program that played completely randomly,
> except that it did not fill in "solid eyes". I discovered that if you
> gave that program a free handicap about 100-120 stones it actually
> became a quite addictive variant of go. The nice thing with a random
> opponent is that you can never trick it or learn some systematic
> weakness. And after playing some game I got the feeling that at least
> once in every game, the random player played at that spot where I
> would play myself if I were black - almost as the computer had read my
> mind. 
> 
> But this is not strange after all since if the computer plays perhaps
> 100 moves in a game like that, it would be very strange if not one or
> two moves would be really good.
> 
> I do not think that Kojima was wrong in his commentary since it is
> much harder to get a sequence of moves right just by coincidense , but
> I just wanted to point out this proverb:
> 
> "Even an  idiot can  play at least one strong move in each game..."
> 
> I do not know if it is useful but it could also be interpreted like
> this:
> 
> "Never expect a weak player to not find a winning move!"
> 
> The risc that a player slightly weaker than you find those moves are
> very high compared to idiots and  random player, and you cannot play
> moves that leaves serious weaknesses behind  that many times in a game
> and get away with it. Sometimes when I lose against "weaker" players
> it seems like I have violated that rule consistently throughout the
> whole game. 
> 
> Another interesting thought about a random player (about 100 kyu) is
> that it is possible to make programs that play even worse, even if you
> disallow "filling in of solid eyes". This means that random play
> cannot be considered the weakest possible, it really takes a little
> (but not much) go-intelligence to play really bad! Also, a random
> player can in theory beat any professional, since nothing stops it
> from playing only good moves. But the probability of that to happen in
> a game is perhaps even lower than the probability of spontaneous
> creation of life in a soup of random chemicals. Current programs are
> perhaps so deterministic that a strong player can always force them
> into playing bad moves, and do not have a chance at all even in
> theory... or perhaps some programs do add a small amount of randomness
> in hope of a surprising win sometime?

--
Magnus Persson
Department of psychology, Uppsala University
Box 1225, SE-751 42, Sweden
Tel 018-471 2141 (work), 018-460264 (home)
MAILTO: magnus.persson@xxxxxxxxxxxxxxxxx
URL: http://www.docs.uu.se/~magnuspe