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

[Jim Segrave]

On Wed 26 Feb 2003 (10:25 +1300), Joseph Heled wrote:
> 
> I think this is what Doug Zare calls "bot confusion", and he uses it to 
> measure exactly that - how good is the bot understanding of that 
> position. Obviously when ply0 == ply1 *for all positions" you have a 
> perfect bot (by induction).

I just re-read that particular article again, but I'm still
curious. Can you tell me which of the following is the best
description of the behaviour in those positions where odd plies are
least desireable:

let t = 'true' equity of a position (or even the
  equity from an extnsive rollout.

let e(n) be the absolute value of the difference between the equity
   given by an n ply evaluation and t (abs value of error)

Is the case that:

1)  e(2) < e(0) < e(1) - the error increases on odd evaluations

2)  e(2) < e(1) < e(0) - odd plies are better than the lower level
                         even ply, but e(1) - e(0) is much smaller
                         than e(2) - e(1) - implying that odd
                         evaluations are more accurate than lower level
                         ones, but the difference is negligible.
or 3) something else?

And can anyone give me an explanation of why this would be so?
 
-- 
Jim Segrave           address@hidden