From: xeno@iastate.edu (Gary L Snethen)
Newsgroups: rec.games.go
Subject: Re: Strategic computations, expensive games
Date: 4 Sep 92 13:58:35 GMT
Organization: Iowa State University, Ames IA

In <1992Sep3.195817.1@acad2.alaska.edu> asek@acad2.alaska.edu writes:


>.... " algorithm is a step by step [ process ] "

>[ step by step ] games are also " a step by step [ process ]"

>generalize by calling them "interactively discrete" and thereby (?)
>amenable to treatment by algorithm.

>Q.  Is the "best way" the "winning way?" <-- monomaniacal egotism def.

>"Best move" meaning (1) choice among six equivalently strong moves
>                    (2) illustrative move for discussion purposes
>                    (3) weak move to give weaker player encouragement
>                    (4) resignation move to indicate resignation (i.e. 1,1).

[...unbelievable bandwidth consumed here... ;) ]

>Again -- why is the "best way" a "winning way" ?  ( Might making right ? )
>History only remembers the victors?  No progeny from those under genocide ?


>:=:  Serious Serbs Serve Several Situations So Some Slippery Spelunkers Sew
>     Sally Sings Sunny Sandstorms Soapy Siblings Senator Saturnalia Sip Seth



Perhaps I missed your point?  Perhaps your point missed?

If GO is viewed as a game whose objective is to win, and there can be
no ties (through a .5 komi or whatever), then one of the two players
CAN force a win.  You CAN analyze this mathematically, you CAN analyze
this logically, but you don't need to.  You can also analyze it as a GO
player.

GO players read out numerous variations while playing their games.  If a
player were capable of reading out all possible variations, he/she would
know which move (if any) led to a win.  If none led to a win, he/she
would see that if the opponent could also read all the variations,
then he/she would force a win.  If you can force a win, then the 'best
move' is to force the win.

If you cannot force a win, then you must analyze your opponent.  If your
opponent is as omnipotent as you, and can read all the variations, your
best move is to resign, for you will lose anyway.  If your opponent is
capable of making mistakes and has limited reasoning, THEN things
grow foggy.  Your best move would be to take the path that offers
your opponent the most attractive mistakes.  That is...  you know
you can be forced to lose, but your opponent does not know all the
'best moves,' so you put him/her into a position where he/she is likely
to make a mistake, at which point, you can then force a win again.

In theory, a 'Book of Perfect Moves Against Perfect Players' can be 'written,'
but a 'Book of Perfect Moves Against Imperfect Players' will only be half-
complete.  (The half containing forced-win moves).

This may sound contradictory, but it is not.  All of the forced win
moves in the perfect player book are also in the imperfect player book,
but against imperfect players, you have a (very good) shot of winning
regardless of whether or not your opponent can force a win.

And these moves against imperfect players are solely dependent upon the
understanding of GO which your opponent posesses, so these moves are
unique for every opponent, thus there is no 'best move' that works
against everyone (unless it is one of the forced win moves, which
one player or the other has every move)...
You must know your opponent.

Of course, you can disagree with me on a philosophical basis, but you
should note that I qualified my discussion with "If the goal is to win."
The goal may to be learn, or to teach, to win by only a slim margin,
or even to lose without your opponent knowing that this was your goal.
Or some combination of these...  Here 'best move' is a largely
subjective thing dependent on your personal goals...

Tic-tac-toe and GO are very similar in omniscient strategies.  That is,
if you know every possible variation of the two games, then your plays
will be based on very similar factors.

You CAN tie in tic-tac-toe...  The reason I set the condition that
you could not tie a GO game (the .5 komi) was because we do not know if
the first move in a go game is a forced win/forced tie/forced loss, and
I did not want to complicate my discussion.  All the same rules apply...
In a forced tie position, you take the forced tie that offers your opponent
the most attractive mistakes.  (If you know your opponent well enough,
you MAY even offer a position in which your opponent could force a win
against you, but will more than likely make a mistake...  but this is
not popularly considered 'good go' because noone knows their opponents
well enough.)

Please don't feel offended that I compared tic-tac-toe to go...

tic-tac-toe has somewhere around 10,000 possible board positions
and go has 1.7e172 or so...  I know all the possible variations of
tic-tac-toe, but no human could hope to know all the possible GO
variations...  This is why it is a game of strategy, and tic-tac-toe
is a game for children.  If we were all super-human, then perhaps GO
would be a game for children and we would all say "But it's obvious
who's going to win."


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There is only ONE best move for 'O'.

Any disbelievers?   Any takers?

---Xeno