Clubs pay the price: report shows luck determines football managers' tenure

This was Sven Goran Eriksson’s last World Cup as England manager, but according to a recent Cambridge study, his next job may not be based on his managerial ability but on the luck of his team alone.

A manager's tenure is intrinsically linked to his team, and his reputation derives from the team's performance. However, according to the Cambridge study, reputation is not determined significantly by the manager's talent, effort or decision making skills, but mostly by pure luck. If luck plays a large part, it would question the high salaries managers are paid.

This remarkably interdisciplinary study by Drs Toke Aidt and Daniel Sgroi with the Faculty of Economics, University of Cambridge, Dr Bill Saslaw with the Institute of Astronomy, University of Cambridge, and Dr Bernard Leong at the Genome Institute of Singapore and the National University of Singapore, explored the qualities responsible for securing and maintaining high level jobs. Initially, it was not intended to focus on football:

"Our original idea was to look at the tenures of CEO's," said Dr Saslaw. "Unfortunately, this information is hard to come by, but football clubs are very keen on promoting their history, and so provide a wealth of information."

The researchers looked into the tenure lengths of managers in England, Switzerland, France, Spain, Germany and Japan, as well as in American football and baseball leagues. The data covered 7183 individuals over 130 years, revealing some interesting facts. One surprising empirical regularity that emerged from the researchers' detailed analysis of this data was that the chance of a manager keeping his job for an extra year follows an inverse power law (the longer the time served as manager, the lower the probability of the manager continuing to serve).

Managerial ability counts for little, it's all about reputation in the public eye…

The study identified that talent, effort and ability play little part in explaining whether or not a manager remains in office; even the best chosen players can damage a cruciate ligament in the first minute of the match by complete chance.

It's not how you play the game, but whether you win or lose that determines the manager's future…

The theory put forward by the research is that the ratio of wins and losses creates thresholds of reputation which determine the length of the manager's time at the top. Each manager gains reputation every time this team wins a game and loses reputation when his team loses. The theory is based on a computer model of 'complex systems': examining events at the macroscopic level to see what patterns emerge out of seemingly random microscopic occurrences. A striking feature of the theory is that it can explain the empirical facts about the tenure length of managers without reference to ability and talent, but with reference to random factors only.

Unfortunately, these results cannot be used to point the accusing finger at any manager's current performance:

"The results are purely statistical," stated Dr Saslaw. "We can't apply them to one individual. However, we could use the results to calculate the probability of a manager's survival in the future."

The research was recently published in the journal Physica A: Statistical Mechanics and its Applications and is available upon request.