R: English Premier League Football Results 2008/9 to 2012/13

football {BradleyTerry2} | R Documentation

## English Premier League Football Results 2008/9 to 2012/13

### Description

The win/lose/draw results for five seasons of the English Premier League football results, from 2008/9 to 2012/13

### Usage

    football

### Format

A data frame with 1881 observations on the following 4 variables.

`season`

  a factor with levels `2008-9`, `2009-10`, `2010-11`, `2011-12`, `2012-13`

`home`

  a factor specifying the home team, with 29 levels `Ars` (Arsenal), ... , `Wol` (Wolverhampton)

`away`

  a factor specifying the away team, with the same levels as `home`.

`result`

  a numeric vector giving the result for the home team: 1 for a win, 0 for a draw, -1 for a loss.

### Details

In each season, there are 20 teams, each of which plays one home game and one away game against all the other teams in the league. The results in 380 games per season.

### Source

These data were downloaded from http://soccernet.espn.go.com in 2013. The site has since moved and the new site does not appear to have an equivalent source.

### References

Davidson, R. R. (1970). On extending the Bradley-Terry model to accommodate ties in paired comparison experiments. Journal of the American Statistical Association, 65, 317–328.

### See Also

`GenDavidson`

### Examples

    ### example requires gnm
    if (require(gnm)) {
        ### convert to trinomial counts
        football.tri <- expandCategorical(football, "result", idvar = "match")
        head(football.tri)

        ### add variable to indicate whether team playing at home
        football.tri$at.home <- !logical(nrow(football.tri))

        ### fit Davidson model for ties
        ###  - subset to first and last season for illustration
        Davidson <- gnm(count ~
            GenDavidson(result == 1, result == 0, result == -1,
                        home:season, away:season,
                        home.adv = ~1, tie.max = ~1,
                        at.home1 = at.home, at.home2 = !at.home) - 1,
            eliminate = match, family = poisson, data = football.tri,
            subset = season %in% c("2008-9", "2012-13"))

        ### see ?GenDavidson for further analysis
    }

[Package BradleyTerry2 version 1.0-6 Index]