By Brendan Kent
Just last season, Borussia Dortmund placed second in the Bundesliga. The year before that, they also placed second and reached the Champions League final. And in the two seasons before that, they won the Bundesliga. This season, they’re fighting a relegation battle.
Dortmund’s squad didn’t see a major overhaul prior to this season, except for perhaps the departure of forward Robert Lewandowski. So are Dortmund actually bad, or have they just been unlucky this year? After all, luck has been known to play a major role in soccer.
In The Numbers Game, Chris Anderson and David Sally discuss in-depth the issue of luck in soccer. They point to several studies that have demonstrated the massive role of chance, including the work of the University of Cambridge’s David Spiegelhalter, who studied the 2006/07 Premier League season and found that “roughly half the points accumulated can be attributed to fortune” (Anderson 60).
Anderson and Sally also cite the work of Universität Münster’s Andreas Heuer. Using data from twenty Bundesliga seasons, Heuer and his team found that “the quality of your squad largely determines the number of shots, and a given shot has a one in eight chance of hitting the back of the net.” This is speaking generally of course, as some shots are better than others, but a study by Martin Lames of Technical University Munich (a study also cited in The Numbers Game), showed that “about half of all goals contain a detectable, visible portion of good fortune” (Anderson 58-62).
Heuer’s findings are particularly interesting in the context of Dortmund’s current form. While they sit in measly fifteenth as of February 15th, Dortmund produce more shots per game than every team in the Bundesliga except Bayern Munich, according to data from WhoScored.com. The graph below shows shots per game against league position for each Bundesliga team through February 15th.
If Heuer is correct, Dortmund have been quite unlucky. They have been successful in finding shots, but the rest, according to Heuer, is mostly down to chance. And because each team has only played twenty one matches, the law of large numbers has not kicked in.
Of course, scoring goals is only half of the battle. But from a defensive perspective, Dortmund seem to also be quite unlucky. Only Bayern Munich and Bayer Leverkusen have conceded fewer shots on goal.
Now, my argument is not that Dortmund are doing everything right. In reality, their poor form has probably been the result of both sub-par performance and bad luck. But Heuer’s work would suggest that they are not a bad team by Bundesliga standards, despite their current league position.
So will Dortmund be relegated? The answer comes down to a question of whether or not the law of large numbers will kick in before the end of the season. Unfortunately for Dortmund, this will not necessarily be the case. If half of the points accumulated at the end of a thirty eight game Premier League season “can be attributed to fortune,” a thirty four game Bundesliga season is hardly a showcase for the law of large numbers (Anderson 60).
Despite the negatives, Dortmund have decisively won their last two Bundesliga games and have shown signs of regressing towards the mean. But the future is still uncertain, and in a chancy game like soccer, many supposedly improbable things will happen, like the relegation of a team that was just recently one of the best in the world. Then again, unpredictability is why many of us love the game.