Who Played Tit For Tat in 2009-10? A Postscript on Fouls in the EPL

A quick PS to the earlier post about fouls committed and suffered in the Big Four leagues of European football. After showing that there is a tendency for fouls committed and suffered to go together, I thought it'd be interesting to see whether all teams were equally likely to play tit for tat or whether there were significant differences.

Take a look based on data for the entire 2009-10 EPL season. The graph shows the distribution of fouls committed and suffered by match and team, along with a line indicating the slope of the statistical (linear) relationship. As you can see, a good number of teams did play tit for tat (measured here as committing more fouls when the other team commits more fouls against a team).

For 15 of the 20 EPL teams the slope is positive, indicating that teams that committed more fouls were also more likely to suffer more fouls. The exceptions were Birmingham, Fulham, Wigan, West Ham, and Wolves. This connection was particularly pronounced for teams like Aston Villa, Hull, Man City, and Stoke. The slope for Arsenal is positive, too; and if we were to disregard the match denoted by the dot in the lower right hand quadrant, it would be among the strongest. And notably, Blackburn were not an "eye for an eye" team in 2009-10 (wonder what Arsene Wenger would say about that). Before too long, I'll take a look at other leagues and seasons, too, so stay tuned!