RE: [Bug-gnubg] Even, odd and half plies (WAS: New Contact Net Er ror Rates)

[Moore, Dave]

> >> (very naive)
> >> 2.  Could positions that evaulate to different equity from 
> different 
> >> sides
> >> of the board be used as training data so that the Net 
> would converge 
> >> to an
> >> agreed upon answer when looking at things from either side 
> of the board?
> > 
> > 
> > Not stupid at all. It seems the general agreement last time 
> was that 
> > this was
> > too dangerous, since there would be a risk that the net 
> became better at 
> > this kind of positions at the expense of other, more common 
> types of 
> > positions.
> > 
> > I have, however, thought of an idea for overcoming 
> differences between 
> > odd and even plies:
> > 
> > The basic idea is to introduce the half-ply: The average 
> between 0 and 1 
> > ply. or in general between n and (n-1) ply. This would decrease the 
> > average square of the error for the kind of position - 
> since the "true" 
> > equity for the position is most likely to be somewhere 
> between these two 
> > evaluations.
> > 
> 
> I will check that. Obviously it is a little more expensive than 1ply, 
> but the hope is to get a better result than 1ply. Personally I don't 
> think it will work, but it is worth a check.

This sounds very interesting. 

As another question/suggestion, when the even and odd plies disagree, could
this fact be used to give a "confidence metric" where gnubg can let the user
know that it may/may not understand the position very well?

Thanks,
Dave