RE: [Bug-gnubg] How to calculate snowie error rate from logged databasedata

[Ian Shaw]

> -----Original Message-----
> From: address@hidden 
> [mailto:address@hidden 
> On Behalf Of Misja Alma
> Sent: 15 August 2009 15:54
> To: bug-gnubg
> Subject: [Bug-gnubg] How to calculate snowie error rate from 
> logged databasedata
> 
> Hi,
> 
> I've been trying to reconstruct my Snowie error rate from a 
> match that I've logged in the database with gnubg.
[snip]
> I then checked what the value for snowie_moves was for my 
> match, and it was the total number of (forced or unforced) 
> moves of me and my opponent added up.

I can't help with the rest of your query, but I do know that this is
correct. Snowie uses the sum of your and your opponent's moves as the
divisor. Forced or unplayable moves (such as being closed out) are
counted.

This is the main reason that gnubg's gradings are so much tougher than
Snowie's. #

Lot's of people dislike Snowie's method, because it is counter-intuitive
to count your opponents' moves as the divisor for your own error rate.
However, it is the rate that people are most familiar with (which I
suppose is why you are trying to extract it.) Douglas Zare also wrote an
interesting article at GammonVillage in which he argued in its favour.

-- Ian