[Computer-go] ieee aticle about computer go by Jonathan Schaeffer

Petr Baudis pasky at ucw.cz
Thu Jul 3 03:22:15 PDT 2014

On Thu, Jul 03, 2014 at 10:57:17AM +0200, Stefan Kaitschick wrote:
> On Thu, Jul 3, 2014 at 9:00 AM, Darren Cook <darren at dcook.org> wrote:
> >
> > If you had a choice between a 1% 65,000-wins move and a 70% 7-wins move,
> > MCTS will keep exploring the 70% move, until it either reaches 65,001
> > wins, and can be chosen, or the winning percentage comes down to 1% also.
> >
> > BTW, that implies it would be very difficult to ever reach the situation
> > you describe, as 1% win rate moves wouldn't be given 650,000 trials
> > (unless all other moves on the board are equally bad, i.e. the game is
> > clearly lost).
> >
> What I dont understand, is why the variation that's trying to catch up has
> to absolutely overtake the leader.
> Shouldn't there be a substantial bonus for a late high success rate?

The way this bonus is often implemented is that if a disparity between
the move with the highest winrate and the move with the highest number
of simulations is different, the program spends some extra time
searching to give a chance to resolve this.

  (Conversely, if some move has been simulated so much more that no
other move can overtake it in the number of simulations in the alloted
time anymore, the search can be stopped early.)

P.S.: No, I don't like Japanese byoyomi for Pachi. ;-)

				Petr Baudis
	Life is short, the craft long, opportunity fleeting, experiment
	treacherous, judgment difficult.  -- Hippocrates

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