Re: [Bug-gnubg] Rating and grading

[Rod Roark]

On Monday 07 July 2003 10:40 am, Albert Silver wrote:
> ... GNU's attributed rating is supposedly based on the FIBS rating system
> and is designed to give a rating that approximates what a user might get
> at FIBS. However, it's self-attributed rating seems to be what
> everything else is relative to and is at 2200. GNU does not have a 2200
> rating at FIBS, not even by a margin. I think that lowering this to
> 2050, representing it's average, would make much more sense. As a
> consequence, all its relative ratings should be lowered accordingly.

Here are the latest cumulative stats for ParlorBot, which
runs gnubg on FIBS with 2-ply checker play and cube
decisions, 33% reduced:

Number of samples  : 3692   (i.e. number of rated matches played)
Lowest             : 1880.71
Highest            : 2120.74
Mean               : 2002.35
Standard Deviation :   51.70

While the average rating used to be around 2030, there has
been a great deal of wandering from that.  Also I suspect
that a few clever FIBSters have learned to take advantage of
the bot's less-than-perfect evaluation in back games and
holding games.

-- Rod