Do football managers lose their spark after three seasons at a club?

It’s human instinct to seek meaning among chaos: to crave an explanation for why something that once seemed unfathomable has happened – and never more so when judging a football manager’s success. As Marcelo Bielsa became the latest managerial casualty in the Premier League upon leaving Leeds last month, that thirst for finding order beyond the headlines led several pundits to suggest his downfall was how long he’d been in the role. More specifically, had he exceeded the optimal time a manager should stay in a job: three years?

The argument carries some weight. Bielsa’s fourth year was when the upward curve Leeds had been on under his management started to dip. But is there really something in the idea that managers should work on a three-year cycle? Former Milan and Benfica coach Béla Guttmann believed so, declaring “the third year is fatal” and arguing that things start to unravel for a manager after passing that threshold.

“A cycle of a manager is probably three years,” Morecambe boss Derek Adams told the Lancaster Guardian last year. “After that, it’s time to move on to a new club. “I don’t think any manager should stay for too long. If you do stay, the club perhaps doesn’t get to move forwards and the manager doesn’t either.”

It would be career suicide for too many coaches to agree publicly, with long-term contracts the compensation for a high-pressure and notoriously unpredictable profession. Although some point to the transient nature of Antonio Conte and José Mourinho’s careers as evidence they subscribe to those assessments.

The three-year zenith can be picked up in the records of several other longer-serving managers. Mauricio Pochettino’s Spurs peaked in his third season and Rafa Benítez won all his trophies