Barcelona’s 2015/16 season is being characterized by a large number of missed penalties, obvious to everyone. Now, this is clearly unusual for Barcelona, since they have missed 8 penalties in the Liga for the 2015/16 season, while missing just 5 in the previous six seasons (from 2009/10 to 2014/15). What about compared to other European teams? Is such a poor performance so unusual? If we consider just the last seven seasons, we find out that there are other examples just as bad, or even worse.
Let’s consider the ongoing 2015/16 season in the European top five leagues. Chart 1 shows the plot of taken vs scored penalties by the 98 teams of these five leagues. The two lines of 100% and 50% conversion rate can help us compare the conversion rate of different teams, since the different number of taken penalties can be misleading. Barcelona are placed relatively bad here, below the 50% conversion line, but they are not the only team below this line. What makes them look ‘that bad’ is the fact they they have taken a lot of penalties (15), much more than the rest (no other team has more than 10).
Chart 2 shows the same type of graph considering the last seven seasons in the Liga (140 data points). Barcelona’s seasons are represented by the red dots. Here it is more visible that Barcelona’s penalty conversion is much worse than in the previous six seasons (all red dots are above the best fit line). As we can see, a considerable number of teams are placed in or below the 50% conversion line, showing similar performance to Barcelona’s. Obviously, the worst example here is Racing Santander, since during the 2011/12 season they managed to score just 1 out of 6 penalties.
A much more comprehensive plot is shown in Chart 3, where are plotted the last seven seasons of Europen top five leagues and Champions League (878 data points). As we can see here, Barcelona are bad, but we have seen worse (and this just considering the last seven seasons).