Re: [computer-go] Modern brute force search

[Don Dailey <drd@xxxxxxx>]

You brought up an interesting point.

I used to speculate with Larry Kaufman about how to program an infinite
speed computer to play chess.   

The obvious way would  be to search to the end of  the game and return
at leaf nodes  -1, 0 or 1.  This would  produce an "omniscient" player
which would never lose a game even to "god."

But would that  be the best way to play against  a human?  Perhaps the
game theoretic value  of chess is draw, which  many believe is likely.
The  omniscient player might  immediately trade  down all  material to
obtain a  draw very  quickly, even  before the human  had a  chance to
screw up.  Or,  it might offer a  draw on the first move  since a draw
offer is  in the  set of best  possible moves.  Game  programs usually
assume best  play by the  opponent, which is  the only correct  way to
play.

But  it  would be  easy  to  imagine  an omnicient  computer  applying
heuristics  which  minimize  the  opponents  chance  of  drawing,  for
instance by  avoid simplification, mixing things up,  keeping the game
as open as possible etc.

I  admit I'm  not an  expert on  GO by  any stretch,  but I  have been
speculating that an "omniscient" computer GO player would be far ahead
of human  masters.  I  suspect that an  omniscient GO player  could be
programmed to play in the  same way strong players beat weaker players
with handicaps, as you say,  "leaving everything unsettled for as long
as possible."

It sounds like GO isn't as complicated as I thought it was, due to the
fact that many of you believe masters are pretty close to optimal play.

For instance,  Jonathon Schaeffer has  taken a game very  MUCH simpler
than even chess, and produced a program that is stronger than the best
human players.  This game is called "checkers" and is played on an 8x8
board.  In the USA just about every child knows this game and it seems
so simple compared  to chess.  In his book,  "One jump ahead" Jonathon
noticed  that no  matter how  deep the  program looked,  it  seemed to
benefit  from looking  even farther.   There was  always  something it
needed 2 or 3 more ply to see.

It seems  this trivial game was  deeper and more  profound than anyone
believed.

I see chess as being much  deeper and much more complicated.  I see GO
as being much more profound than chess.  Am I wrong about this?

If it's the  case that GO is simpler than even  Chess, I would retract
my  speculation on this.   I know  that it  is often  held that  GO is
simpler than chess for humans, just harder for computers.  But I don't
agree with this.  A strong chess  player who is also a realtively good
GO player  and an expert  at many games  (Larry Kaufman) once  told me
that there  are many  more levels of  skill in  GO than in  chess.  In
other words, as he explained, the  median GO play has less of a chance
beating a top GO player than  a median chess player has of beating the
top chess player.

I  have been  told that  it takes  longer to  "master" GO  than chess,
although I  don't really know what  this means.  I  know it's possible
for a very  young person to be world chess champion.   How old are the
world champion GO players?

So my view (and I'm sticking with  it) is that we may someday find out
that great GO players are not as  great as we think they are, but it's
just my opinion.  I certainly  don't believe they are playing anywhere
near optimal, although it probably seems that way to us mere mortals.

- Don







   X-Sender: rtayek@xxxxxxxxxxxxxxxxx
   Date: Sun, 07 Nov 2004 15:42:21 -0800
   From: Ray Tayek <rtayek@xxxxxxxxxxxxxxxxx>
   X-Scanned-By: MIMEDefang 2.42

   At 10:51 AM 11/7/04, you wrote:
   >...
   >And that is a shame.    I strongly feel that even when humans are clearly
   >surpassed,  we are just getting started.  Chess is an incredibly deep game
   >and the very best humans are very weak compared to the "ultimate player."
   >
   >Just my thoughts.  All of this  is even more true of Go.  There exists
   >(in  principle) a  future GO  player than  can make  the very  best Go
   >player (of today or yesterday) look like a baby.

   i don't think so. if by "look like a baby", you mean able to give a large 
   handicap (say 6 stones), then no way.

   i don't see any evidence that human players can become that much stronger 
   than todays professional 9-dan's and i doubt that a program will beat them 
   for a *very* long time (think about "asking" moves, or watch a 9 dan pro 
   give an amautuer 7 kyu player a nine stone handicap - the pro will leave 
   everything as unsettled as possible for as long as possible).

   thanks

   ---
   ray tayek <http://tayek.com/>, co-chair <http://www.ocjug.org/>, actively 
   seeking telecommuting work.

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