Aggressive Play in European Soccer Leagues

By John Considine

A recent article in the Journal of Sports Sciences presents some interesting data on fouls and tackles in the top five European soccer leagues.  The authors use the data to investigate what they call aggressive play.  They conclude that their "data support that European soccer has become less aggressive and the English Premier League is the most aggressive league".  It does not seems that clear to me.

Figure 1 in the article has three parts.  Part (a) shows the number of fouls per game for each season between 2007/8 and 2015/6.  Part (b) shows the attempted tackles per game for the same seasons.  Part (c) shows the attempted tackles per foul.

Figure 1(a) is presented below and shows that there are less fouls per game in the English Premier League.  The number of fouls in the other four leagues show a clear decline.  The number of fouls seems to be used to suggest that "European soccer has become less aggressive".

The number of fouls do not suggest that the English league is the most aggressive.  The statement that the "English Premier League is the most aggressive" seems to be based on attempted tackles per foul.  This is presented in the Figure 1(c) below.  There are more attempted tackles per foul in the English Premier League.

Should we use Figure 1(a) of Figure 1(c) to examine aggressive play?  Depending on how we use the graphs we could tell a different story.  We could use Figure 1(a) to say that the English league is the least aggressive and Figure 1(c) to say that aggressive play is slightly increasing.  This is the opposite of what the authors claim.