[R] Rating competitors

[Spencer Graves]

      Have you considered Bradley-Terry models?   RSiteSearch("bradley", 
"functions") just returned 31 hits for me. 

      Hope this helps. 
      Spencer Graves

Jeff Newmiller wrote:
> I am looking for hints on how to estimate ratings for competitors
> in an ongoing pairwise competition using R... my particular area of
> interest being the game of Go, but the idea of identifying ratings
> (on a continuous scale) rather than relative rankings seems easily
> generalized to other competitions so I thought someone might be
> studying something related already.
>
> I presume the rating of a competitor would be best modeled as a random
> variate on the rating scale, and an encounter between two
> competitors would be represented by a binary result.  Logistic regression
> seems promising, but I am at a loss how to represent the model since
> the pairings are arbitrary and not necessarily repeated often.
>
> I have read about some approaches to estimating ratings for Go,
> but they seem to involve optimization using assumed distributions
> rather than model fitting which characterizes analysis in R.
>
> Does any of this sound familiar? Suggestions for reading, anyone?
>
>