In message
<[email protected]>, Vlad
Dumitrescu <[email protected]> writes
On Tue, Nov 24, 2009 at 23:58, Nick Wedd <[email protected]> wrote:
Vlad Dumitrescu <[email protected]> writes
Please try to explain why the "hahn calculation" isn't working in a
normal game so as to ensure a win. I'm talking about strong human
players.
Are you talking about omniscient players? If not, I have already answered:
Suppose my attempts to read the game tell me "If I seal off my
territory at A, I will win by 5 points. If instead I invade at
B, then 70% of the time I will win by 25 points, 30% of the time
I will lose by 5 points".
If I am playing Go, I will prefer A. If I am playing bang neki,
[or Hahn scoring] I will prefer B.
Hi Nick,
I'm not talking about omniscient players. My problem with your answer
above is that "70% of the time I will win by 25 points" contains
implicit assumptions, which affect the exact numbers and thus the
choice one would make.
How is the 70% calculated? Against whom? The ratio will be different
against someone 3 stones stronger, against someone of my strength or
someone three stones weaker. Do the playlines leading to a 25 points
win involve a stupid mistake that the opponent must make, or are they
about luring him gently in a non-optimal position? Or is it a big
fight that is involved, I can't read it but feel 70% confident I can
win it?
"How is the 70% calculated?" - that must depend on the player. If it is
an MC program, it will use roll-outs. If it is a human player weaker
than the opponent, it will take into account the possibility of a tesuji
that the player has been unable to find. If it is a human player
stronger than the opponent, it will take into account a blunder that the
opponent may make.
But none of this affects the argument. A program to play Hahn Go has no
reason to calculate probabilities, it should just make the biggest move
it can. A program to play using any other form of scoring does better
to calculate probabilities, as best it can, and use these to maximise
its result under that scoring system.
Opponent modeling will also play a role and then the percentage can't
even be computed anymore, the player has to guess, to gamble. It is
here that one's personality comes to play. "This guy doesn't like to
invade deep, let's expand this moyo". "That guy is a fierce fighter,
better to play it safe".
Yes, of course, calculating probabilities is difficult.
Nick
Personally, I would almost always play A in a tournament situation (or
with money involved). In a Hahn tournament, it depends on the overall
situation, if a small win in this game isn't enough then I must try B
if I want to win. If it's for fun, then exploring B is much more
interesting and offers more opportunity to learning.
best regards,
Vlad
_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/
--
Nick Wedd [email protected]
_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/
