> Maybe this was clear to Don already, but his message sounds a little like it would be possible to estimate > rating from winning rate and average opponent. It is not.
No, I didn't mean to imply this. - Don Rémi Coulom wrote: > Don Dailey wrote: >> Another example I found is the impressive Valkyria program. Version >> 2.7 won 92% of it's games, more than even the top rated greenpeep0.5.1. >> >> However, the average rating of Valkyria's opponents was only 1722. >> This is quite a difference. So Valkyria is rated only 2222 compared to >> greenpeep 2621 despite the fact that it wins more! >> Of course 2222 is still impressive and Valkyria is number 17 out of all >> the programs that have played over 200 games (over 200 of them.) >> - Don > Hi, > > I would like to add a note to this discussion to explain that the > computed rating is not a function of winning rate and average > opponent. Simply take this simple example into consideration: > > player A: > 1 win and 1 loss against a player of rating 1500 > 1 win against a player of rating 500 > 1 loss against a player of rating 4500 > -> 50% against an average of 2000 > > player B: > 1 win and 1 loss against a player of rating 2000 > 1 win against a player of rating 1000 > 1 loss against a player of rating 3000 > -> 50% against an average of 2000 > > Although they have the same average opponent, and the same winning > rate, player A's evaluation should be much lower than player B's. > > Maybe this was clear to Don already, but his message sounds a little > like it would be possible to estimate rating from winning rate and > average opponent. It is not. > > Some rating algorithms try to do it anyway (like EloStat, and the > rating system of the French Chess Federation), but they are very badly > flawed. Real-life examples where they fail badly can be found on > bayeselo's page: > http://remi.coulom.free.fr/Bayesian-Elo/ > (look for "average of ratings" in the page) > > Rémi > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
