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Q: For the board game go, what size of a board can a computer beat a human? ( Answered 5 out of 5 stars,   1 Comment )
Subject: For the board game go, what size of a board can a computer beat a human?
Category: Science > Technology
Asked by: benpark22-ga
List Price: $5.00
Posted: 11 Aug 2002 00:46 PDT
Expires: 10 Sep 2002 00:46 PDT
Question ID: 53195
This question is about the ancient Chinese board game go (or Weiqi).

We know that for a full size go (19 by 19), even an inexperienced
human player (a few months into learning) can easily beat the best
computer program.

As the size of the board reduces, the game becomes easier for the
computer to handle. The question is: In the current level of computer
go playing programs, at what board size can a computer beat a human?

Request for Question Clarification by blader-ga on 11 Aug 2002 01:11 PDT

It depends on how good the human is. =) I am regularly beaten by "The
Many Faces of Go" engine on a 9x9 board.

Best Regards,

Request for Question Clarification by blader-ga on 11 Aug 2002 01:15 PDT
Did you mean a professional human? Of any dan level?
Subject: Re: For the board game go, what size of a board can a computer beat a human?
Answered By: blader-ga on 11 Aug 2002 01:46 PDT
Rated:5 out of 5 stars
Dear benpark:

As a beginning go player (10 kyu amateur), one of the most interesting
aspects of the game is how much difficulty computers have with this
game. I believe that Go is unique among board games in this aspect.

As you know, the game of Go is played at three board sizes: 19, 13,
and 9. To answer your question, a computer has not yet beaten a
computer at the minimum board level of Go, which is on a 9x9 board.
Althought it is possible that a computer may be able to beat a human
on an even smaller board, this has never been done with a
professional. I don't find this likely, however, as we need to
remember that the game gets easier for the human as well, on smaller

The best and only example of a game in which a computer has played a
top professional go player on the minimum board size is a game with
Saiko Masataka (8 dan professional!) against the programs "Many Faces
of Go" and "GoAhead." This is known as a "multibrained game," because
to help the computer out, a human player chooses the best move between
the two programs.

The computer was given a two stone handicap at this board size, and
was allowed to go first with 0 komi, but despite all of these
advantages, it still lost to Masataka.

You can find an SGF file to see the course of this game here:

If you don't already have one, here's a SGF file viewer:

Google Search Strategy:

    "many faces of go" "exhibition games"

I hope this helps!

Best Regards,

Request for Answer Clarification by benpark22-ga on 11 Aug 2002 08:31 PDT
Thank you for your response. It is helpful. 

But it does not answer my question. It does not tell at what board
size the best computer program and the a professional human player
have equal hands.

The answer certainly is not 9. Can it be 8, 7,... ?

Maybe there is no answer, because it has not been tried out, and
people have not thought of it.

Clarification of Answer by blader-ga on 11 Aug 2002 12:40 PDT
Dear benpark-ga:

After further research, I have found that technically speaking, a
computer can beat a human at 3x3, 5x5, 7x7 Go. (Go board sizes are
always in odd numbers).

The reason for this is that all the possible sizes under size nine are
"solved" by humans. Because Go's komi is designed to enlicit a draw,
perfect play will always result in a draw if the human plays perfect
positions (and this is already known) on any board size less than 9x9.

5x5 and 7x7 have been solved, by people, not computers, so there may
some errors :)  I've seen some of the diagrams from the 5x5 solution,
but don't
have a copy.  It's been published somewhere.  The 7x7 solution, I
heard of
second hand,
and never saw it, and as far as I know it is not published.  Of course
first move in both cases is at the center.

At 11:12 PM 10/10/2001 -0400, you wrote:

>Where can I find information about 5x5 perfect play?
>I mean what's the perfect play sequence for black? I'm not sure if
>has been solved. Has 4x4 been solved?
>                                    myriam

David Fotland


Best Regards,
benpark22-ga rated this answer:5 out of 5 stars
Hi blader,
Thanks for the answer. Should have paid you more for it. I was just
asking it for fun, and I am sure you had fun answering it.

Subject: Re: For the board game go, what size of a board can a computer beat a human?
From: siliconsamurai-ga on 11 Aug 2002 12:13 PDT
I know a top GO game designer and he couldn't find any top players
willing to test it out.

Most of the ones I personally know are heavily Zen-oriented and don't
consider it a suitable match.

I'm not saying it is or isn't, just that the masters I know would
never play a computer.

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