RE: Skill level names

[Ian Shaw]

I'm in favour of updating the classification; using the BMAB scales seems like 
a good measure. 

The scaling of the PR values comes historically from Snowie, which used the sum 
of both players' moves as the divisor. Gnubg uses only the player's unforced 
moves, which naturally means gnubg error rates are at least double Snowie error 
rates. When XG was created Xavier calculated the error rates using the same 
method as gnubg, but then divided by 2 to scale them to the match Snowie Error 
Rate, which is what most people were familiar with. 

Gnubg error rate is more accurate as a measure of how many points your error 
will cost you, but we seem to have lost that battle in the public 
consciousness. 

I think it's time to drop Snowie Error rate from the statistics display, and 
replace it with PR. And if we do that, then we could use the BMAB ratings 
directly rather than re-scale them from PR to error rate. 

Cheers,
Ian 



-----Original Message-----
From: bug-gnubg-bounces+ian.shaw=riverauto.co.uk@gnu.org 
<bug-gnubg-bounces+ian.shaw=riverauto.co.uk@gnu.org> On Behalf Of Francesco 
Ariis
Sent: Sunday, July 7, 2024 11:56 PM
To: bug-gnubg@gnu.org
Subject: Re: Skill level names

Il 08 luglio 2024 alle 00:05 Philippe Michel ha scritto:
> For the analysis results we could use the denominations from BMAB
> (https://urldefense.proofpoint.com/v2/url?u=https-3A__bgmastersab.com_about&d=DwIDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=DPylQUHTi_E0xrxfi9iWyIPcSxXPmeJo9B7gmdo99Oo&m=Jp51Qep4rYNDQKxKxouCkKOzFvJy-VbxX7PPthGwlTZt2NzNBoCRT0UZte1BgNE9&s=I17WfSVGEl2cGp1DQV0izGo6UXhVKyFG7shuQ845Rtc&e=)
>  without the 0/1/2/3 subdivisions:
> error rate <= 5 Super Grandmaster
>            <= 8 Grandmaster
>            <= 13 Master
>            <= 20 Advanced
>            <= 32 Intermediate
>            else either Casual or Beginner

This seems a very good idea, a set of recognisable titles that make sense for a 
human.

I am a bit puzzled by some BMAB Level denominations though.
If I read the table correctly, “Intermediate” lies between 10–16 PR. This 
should translate — again if I got it correctly — to a gnubg error rate of 
20–36, which is “Beginner”/low “Casual Player”, the bottom of the interval 
being “Awful!”
I guess that is some vanity sizing from the BMAB.

But let this not be a blocker, the idea remains very good —F