Since Diego Simeone took charge of Atlético Madrid, among other features, their team is widely regarded for their strong defense. In the current season they have conceded 12 goals in 29 games, recording a very low average of goals conceded per game (0.414).
In order to give some perspective, I plotted three charts containing goals scored per game vs goals conceded per game considering the last 17 seasons of the Europe Top 5 Leagues (starting from the 1999/2000 season; 1632 data points).
As we can see from Chart 1, the Chelsea team of the 2004/2005 season are the only team to have a lower goals conceded per game ratio (0.395) than the current Atlético Madrid team (0.414). No other team have a ratio lower than 0.500.
More over, 4 out if 12 goals that Atlético Madrid have conceded in the Liga 2015/2016 have been against Barcelona. If for a moment we exclude these goals conceded against Barcelona (Chart 2), Atlético Madrid’s ratio drops incredibly to 0.276.
It may also be interesting to see how Atlético Madrid’s goals conceded per game ratio has changed during seasons (Chart 3). The 2015/2016 ratio is very low even when compared to the the 2013/2014 season (when Atlético Madrid won the Liga and reached the Champions League Final).
Maybe, Atlético Madrid are the best (or the second best) defensive team of the century.