[email protected] wrote on 
04/02/2009 00:14:32:

> One of the available criteria to end a rollout is when standard 
deviations 
> are small enough. For instance, it could be :
> 
> Stop rollout when STD's are small enough
> After 1296 games, rollouts will stop if the STDs are small enough.
> Rollouts can stop when the ratio |STD/value| is less than 0.0040 for
> every value (win/gammon/backgammon/...equity)
> 
> I think there are two problems with the way this is curently implemented 
:
> 
> - the "ratio ... for every value" works poorly when one of the values, 
> usually backgammons for one of the players, is small but not zero. All 
> other STD/value ratios are roughly identical but that of this irrelevant 

> (equity-wise) term can be 10 or 20 or 30 times larger and cause the 
> rollout to take much more time.
> 
> I'd suggest we check only the equity. If it is accurate, the single 
> win/gammon/backgammon numbers will be as well if they are any 
significant.

Makes much sense to me. I was even tinking the stopping criteria was 
already
working in the manner you describe.
 
> - if one doesn't care for the individual kind of outcomes, the STD/value 

> ratio doesn't seem pertinent. Do we really want to know equities around 
> 0.2 with an accuracy five times higher than those around 1 for instance 
?
> 
> The simple STD on a 1-cube, whatever the equity, seems a better 
criterion.

I suppose that if one is not interested in estimatnig individual equities
then his/her interest is in estimating the relative ranking of the 
alternatives.
In this case, the jsd-based criteria seems better.

Anyway, I've never digged too much into these options, I just wait for the 

unstopped rollout to finish :)

MaX.
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