baseball: Baseball Data from Agresti (2002)

Description

Baseball results for games in the 1987 season between 7 teams in the Eastern Division of the American League.

Usage

baseball

Arguments

Format

A data frame with 42 observations on the following 4 variables.

home.team: a factor with levels Baltimore, Boston, Cleveland, Detroit, Milwaukee, New York, Toronto.
away.team: a factor with levels Baltimore, Boston, Cleveland, Detroit, Milwaukee, New York, Toronto.
home.wins: a numeric vector.
away.wins: a numeric vector.

References

Firth, D. (2005) Bradley-Terry models in R. Journal of Statistical Software, 12(1), 1--12.

Turner, H. and Firth, D. (2012) Bradley-Terry models in R: The BradleyTerry2 package. Journal of Statistical Software, 48(9), 1--21.

Examples

Run this code

# NOT RUN {
##  This reproduces the analysis in Sec 10.6 of Agresti (2002).
data(baseball) # start with baseball data as provided by package

##  Simple Bradley-Terry model, ignoring home advantage:
baseballModel1 <- BTm(cbind(home.wins, away.wins), home.team, away.team,
                      data = baseball, id = "team")

##  Now incorporate the "home advantage" effect
baseball$home.team <- data.frame(team = baseball$home.team, at.home = 1)
baseball$away.team <- data.frame(team = baseball$away.team, at.home = 0)
baseballModel2 <- update(baseballModel1, formula = ~ team + at.home)

##  Compare the fit of these two models:
anova(baseballModel1, baseballModel2)


# }