How can you tell if a football manager is really good at his job?

An important thing to remember about Andre Villas-Boas is that he had ridiculously good hair.

You don’t spend a record €15 million to sign a new manager away from Porto unless you’re pretty sure you know what you’re getting. And one thing Chelsea knew for sure was that in the heady days of 2011, the man with a swirling, fox-red side part looked impossibly cool as he was tossed into the air during the trophy celebrations.

That kind of hair had sexy new ideas—a philosophy, perhaps. It had the kind of mischievous sway that a press conference could command, smoldering volcanically above the pointed ends of an unbuttoned collar. But when the 33-year-old prodigy gave his first interview as the world’s most expensive manager, all the glamor quickly disappeared.

“Don’t expect anything,” Villas-Boas warned gently, “from one man.”

True to his word, he was fired in March.

Villas-Boas to Chelsea could have gone down as a historic blunder, were it not for the fact that all other managerial teams have wasted transfer fees in recent years alone: ​​Marco Rose to Borussia Dortmund (5 million euros up front for one mediocre season); Adi Hutter to Borussia Mönchengladbach (€7.5 million, same); Julian Nagelsmann to Bayern Munich (€25 million for 19 months); Graham Potter to Chelsea (let’s not talk about it). This was the cream of the crop, which the head coaching clubs couldn’t wait for, but in their new job they had the shelf life of a bunch of bruised bananas.

How do we know if a manager is good? The question almost sounds too obvious to ask – everyone in the pub will be happy to explain it to you loudly over a beer – but professional organizations with millions at stake smell it every year. Apparently the answer is not great hair. They can’t be trophies either, as these are almost only available to managers who already work at top clubs. If the study of aspiring coaches can be called a science, it remains largely theoretical.

“We’ve worked with football clubs and leagues around what predicts a head coach’s success, and that’s very, very difficult,” says Omar Chaudhuri of sports consultancy 21st Group. “There are very few strong predictors.”

Everyone loves a winner, so it makes sense that employers start looking for coaching talent at the top of the table. But we also know that in the vastly unequal world of European football, the wage bill is the fate of most teams, regardless of who is involved in the technical field. The managers we admire most are the ones who find a way to punch above their weight.

To weed out those overachievers, we can start by modeling the relationship between squad strength and success, using crowdsourced ‘market values’ from Transfermarkt, which provides a decent proxy for player quality when you don’t have wages on hand. We will average this season’s values ​​with last season’s values, if available, to give coaches some credit for player development, and then weight the values ​​by minutes played to account for absences.

For the performance side we use a 70/30 mix of the expected goal difference without penalties and the actual goal difference. captures the strength of the team quite well and places more emphasis on the parts of the game over which coaches are likely to have some influence (creating and denying chances) than on the parts over which they are unlikely to have any influence (finishing, saving shots, successfully lobbying for penalties by VAR rectangle thing to do with their fingers).

The results are striking. Over the past seven seasons in Europe’s top leagues, our simple player quality model can explain around 80 percent of teams’ success.

But what about the remaining 20 percent – ​​who should get the credit for that?

Looking at the outliers in the graph above, it seems fair to say that Gian Piero Gasperini’s freewheeling style helped elevate Atalanta’s mid-budget squad to a Champions League contender a few years ago, and the entire pack of head coaches and interim boys who oversaw Schalke’s disastrous 2020-2021 campaign probably weren’t very good at their jobs. Perhaps performance over team value is a good measure of what a manager has to offer.

Reassuringly, this season’s list of top teams with a higher-than-expected adjusted goal difference is a veritable who’s who of coaching legends and the game’s best emerging managers.

Xabi Alonso has rejected overtures from Bayern Munich and Liverpool to stay at German champions Bayer Leverkusen, while Brighton’s Roberto De Zerbi, who was called ‘one of the most influential managers of the last twenty years’ by no less an authority than Pep Guardiola ”, remains a strong contender for both jobs.

In Catalonia, Barcelona have paid attention to Michel from Girona. Sebastian Hoeness, Paulo Fonseca, Thiago Motta and Will Still have many admirers, and perhaps we should all pay more attention to what Eric Roy is cooking in Brest.

Is that it then? Have we cracked the not-so-secret formula to finding Europe’s next top manager?

Well, wait a minute.

An important property for a good sports statistics is stability, or how much it varies from season to season. If last year’s performance can’t predict next year’s performance because the number is too sensitive to context, you probably don’t want to make it the sole basis for expensive hiring decisions.

By that measure, our manager metric is a failure. For head coaches changing jobs, there is no correlation between the previous year’s performance above or below expectations at their old club and their first season at their new club. While the added goal difference seemed quite good in identifying this season’s best managers, it has no predictive value whatsoever for new recruitments.

When Chelsea spent £21.5 million to sign Graham Potter, he was coming off one of the best runs of any head coach in the last seven years: in 2020/21 and 2021/22, Brighton improved by 22 and 13 adjusted goals off than expected. His seven months in London did not go so well.

Brighton, meanwhile, signed Roberto De Zerbi, even though his final season at Sassuolo was about average compared to their team value. He’d had a decent season the year before, and a respectable spell outside the top five in the league at Shakhtar Donetsk in between, but nothing that could have suggested his first season at Brighton would be the fourth best of hundreds in In recent years. our dataset.

What can explain the difference between these two very different job application stories? Perhaps there is a clue in how Brighton’s famously analytical owner Tony Bloom explained his process. “I am confident,” he said of De Zerbi’s signing, “that his style and tactical approach will fit in extremely well with our existing squad.”

The Zerbi (camera pointed) and Potter in 2022 (Bryn Lennon/Getty Images)

Smart clubs don’t just hire successful managers in the hope that they have an innate knowledge of how to win. They ensure that a coach’s tactics match the players they already have, knowing that changing styles will cost them money and time.

“I don’t want to have to replace 15 players or something like that in two years,” said one veteran analytics consultant, who requested anonymity to protect client relationships. “Because then it becomes a project where you cycle through players and hope that everything turns out well.”

Not every club is as careful with this step as Brighton. Chaudhuri explains that searches often start with a ‘performance piece’ to determine whether managers are getting the best out of their current squad, but ‘then you have a playing style piece, where clubs are generally quite vague about how they want to play. They say, ‘We want games to be engaging and exciting,’ whatever that means. And then you say, “Okay, tell us what you think that looks like.”

The other advisor agrees. “I had a meeting yesterday, I gave five candidates, like, ‘What do you think of these five?’” he says. “And he said, ‘Well, I like these four.’ But I said, ‘One of these four is actually not the style you said you wanted.’”

Figuring out which managers exceeded expectations is the easy part. You can watch their players throw them into the air during a trophy celebration and imagine your club doing the same next season. But success itself is fickle. It also tends to be expensive. The right question is not, “How do we know if a manager is good?” but “How do we know if a manager will be good for this group of players?”

The secret ingredient to hiring the right coach is style – and not just the kind that comes with really good hair.

(Header photo: Lars Baron/Getty Images)

The Athletic recently profiled six of the most innovative, emerging managers in European football.