Beeld © Jenna Arts

How the volunteers of data website Transfermarkt became influential players at European top football clubs

Data website Transfermarkt has become the unofficial appraiser of European top football. Its valuations can be found in annual reports and at the negotiating tables of major clubs. How trustworthy is its data?

Höhenkirchen-Siegertsbrunn, half an hour from Munich, is a village of square concrete houses and gardens that have been almost obsessively tended to. On its outskirts stands the BlueBox youth centre. Despite its name, this is one of the few buildings in town that are not entirely square. It is blue, though.

From the ceiling, fluorescent tubes hang on metal wires between the oak beams. There’s a pool table, a TV with PlayStation, and a sound system.

Martin Freundl – rectangular glasses, black face mask, short blond hair – welcomes us at noon with a cup of green tea. Freundl studied to be an economics teacher a few years ago, but after graduating couldn’t get a permanent contract anywhere. So he changed tracks: he recently graduated as a social worker and went to work at the youth centre.

Later this afternoon, the building will be overrun by youngsters aged 10 to 17. Freundl’s job is to care for them and keep them from going at each other’s throats.

In the meantime, he opens an Excel file on his computer. The leftmost column contains the names of every club in the Bundesliga, Germany’s top professional football division. Next to it, it lists the names, ages, and positions of every player, including top strikers like Robert Lewandowski and Erling Haaland. On the far right are two more columns containing estimates of each player’s current and possible future market value.

Freundl manages the spreadsheet for Transfermarkt. With one billion page views per month, it is one of the world’s largest football websites. Freundl is responsible for determining the market valuation of every Bundesliga player.

It’s a voluntary job he signed up for in 2017, believing that the values on the site deviated too much from reality. ‘My goal is to make that gap as small as possible,’ he tells us. ‘I think of it as a kind of game. You make a prediction, and it’s satisfying to be proven right.'

A 28-year-old social worker and football fanatic voluntarily figuring out the market value of football players for a statistics website. It seems innocent enough, but these valuations have a major impact on professional football organisations. An investigation by Follow the Money found that the figures produced by Freundl and his colleagues are used in the annual reports of top European clubs, at transfer negotiation tables, by scouts, and in boardrooms. Do the professionals know how their figures are made?

Price tags

Transfermarkt.de was born in 2000 as the brainchild of Matthias Seidel, a German computer engineer. He founded Transfermarkt.de as a hobby, a place to collect news about his favourite club Werder Bremen. A year later, he added a public database containing information about players, coaches and leagues.

Over the following years, the site developed into a professional organisation. In 2008, the German publishing house Axel Springer acquired 51 percent of the company shares. After that, things moved fast: Transfermarkt gained web developers, an online editorial team, and a worldwide register for agents. It now employs about seventy people, the site is available in fourteen languages and the player database contains details of more than 800,000 professional footballers.

Transfermarkt gets its data about these players from its users. They keep track of how many minutes each player spends on the pitch, how many cards they get shown, their medical history, contract duration, and much more. The coverage doesn’t just extend to top players like Lionel Messi and Frenkie de Jong, either. Joseph Ochaya, a 26- year-old left-wing defender from Uganda who plays for the Congolese club TP Mazembe, can just as easily be looked up.

Nick Kersten, head scout and deputy director at Nijmegen football club NEC, says every scout is ‘addicted’ to Transfermarkt. ‘The site is always open on my browser, usually with about fifteen tabs. It's the one I use the most by far. First of all to see the players’ ages, secondly their contract durations, which are generally very accurate, and thirdly the name of their agent. That tells us right away who to contact when we’re interested in a player.' The information is almost always correct, he says: ‘I think that's quite an achievement on their part.’

In addition to statistics on cards and contracts, Transfermarkt also publishes an estimate of every professional player’s price tag. According to the site, Messi has a market value of €100 million. Frenkie de Jong should cost about €70 million; Joseph Ochaya, the Ugandan, about €200,000.

These market valuations are what the site is mainly known for; they are widely praised for their comprehensiveness and accuracy.

Kersten says he doesn’t pay too much attention to the market values. ‘We sometimes use them in contract negotiations, but I’m not fixated on them.’ Transfermarkt is theory, he says; it works differently in practice. ‘It's an old-fashioned game of supply and demand. If a player is in the spotlight, their value automatically rises. If there’s little interest, the club will get rid of them for less.’ But if a new player is offered to his club, Kersten would prefer to see his Transfermarkt profile. ‘That's all I need to know.’

Where does Transfermarkt get its numbers? No one ever asked

Kersten is not the only sports director who pays attention to Transfermarkt. Top European clubs make regular use of the site. Take former FC Barcelona chairman Josep Maria Bartomeu, who appeared on the Catalan radio station RAC 1 in July 2020. Among other things, he talked about Lionel Messi’s contract extension and Brazilian player Arthur Melo’s move from Barcelona to Juventus for a whopping €72 million, excluding bonuses.

When asked if Melo was worth that much, Bartomeu replied: ‘His Transfermarkt value was €70 million.’

In another case, a former consultant to Spanish club Valencia CF filed a criminal complaint against Portuguese agent Jorge Mendes and the club’s owner Peter Lim in August. Mendes had brought a number of Portuguese players to the Spanish club; the consultant claimed that Mendes and Lim had illegally inflated their market valuation. The public prosecutor threw out the case, on the grounds that the paid transfer fees were close to the estimated market values on Transfermarkt.

Transfermarkt is not the only company that publishes price estimates for football players. Accountancy and consultancy firm KPMG, as well as FIFA’s CIES Football Observatory, also issue sporadic reports on transfer fees and the state of the market. However, Transfermarkt distinguishes itself by the size of its database, its free access, and the frequency with which it updates its market value estimates.

And thus, the website has become the unofficial player appraiser of the football world. The aforementioned examples are just a few of the numerous cases where top clubs cite Transfermarkt as a source. International media, too: from ESPN to L’Equipe and from The Guardian to La Gazzetta dello Sport, many large publications rely on figures from the website.

Where does Transfermarkt get its numbers? No one ever asked, employees of the site tell Follow the Money.

"I’m just a social worker. I do this for fun, and the football industry is worth millions. That contrast is insane"

Wisdom of the crowd

Martin Freundl, the social worker who manages the Bundesliga statistics, says it’s ‘crazy’ that professional clubs take his valuations seriously. He puts his hands on his head and laughs in disbelief. ‘I just spend a bit of my free time on my computer at home, estimating prices. And the football industry then takes these valuations seriously. It’s unreal. I’m just a social worker, I do this Transfermarkt work for fun, and the football industry is worth millions. The contrast is insane.’

Other employees and volunteers at Transfermarkt tell Follow the Money that the website never planned to have such a pivotal position in the international football world. Christian Schwarz, who as 'international head of market values' is the first point of contact for players and clubs who disagree with a valuation on the site, can hardly comprehend the influence of his work. ‘Clubs shouldn't make transfer decisions based on the figures on our website,’ he says. ‘Our method is not scientific.’

Schwarz explains that prices are set according to the ‘wisdom of the crowd’ principle, which is similar to how Wikipedia works. Users can discuss market values on the Transfermarkt forum, but the ultimate number is based only on substantiated arguments, and is ultimately determined by Freundl and his colleagues. Their informal job title is Pate, ‘godfather’: they are the compass that guides the good ship Transfermarkt.

Each league has its own voluntary ‘godfather’. They base their figures on a number of factors, including the kind of spreadsheet with ages and positions Freundl showed us earlier. Other criteria, according to a Transfermarkt document obtained by Follow the Money, include minutes played, goals, assists, matches played for the national team, contract length, salary, and the club’s prestige and financial situation.

An example: according to Transfermarkt, a left wingback playing for a mid-table side in the Bundesliga is worth between €5 million and €10 million. Players at Ajax, the most successful club in the Netherlands, are generally valued more highly than those at Feyenoord. Similar players are also compared to arrive at a final market price.

‘Clubs shouldn't make transfer decisions based on the market values on our website'

Eventually, the numbers end up on the desk of Christian Schwarz, who ensures that the figures for each league are reasonably consistent. Sometimes, he suggests a minor correction. But Schwarz can’t check all 800,000 players by himself, so he has to rely on the knowledge of his voluntary godfathers.

Players in top-level leagues are revalued four times a year: two major updates before transfer periods, and two minor ones in between. The process takes place in the same way for each country, with a few exceptions.

Something Transfermarkt explicitly does not use, is an algorithm – even though almost every scout, sports director and other industry observer we spoke to thought the website does. That isn’t to say that an algorithms would automatically perform better at predicting market values: in 2016,  scientists from the universities of Copenhagen and Vaduz tried to produce estimates using a multiple regression model. They ultimately concluded that their model was less accurate than the wisdom of Transfermarkt’s crowd.

Paper reality

Transfermarkt may be better than an algorithm, but that doesn’t mean its figures are always correct or even close. In practice, they’re inaccurate predictors of actual transfer prices, a data analysis by Follow the Money points out. On average, Transfermarkt’s estimated market value differs by some 60 percent from a player’s actual transfer fee. For transfers worth more than €10 million, the difference is 34 percent. More than half of the site’s calculations are lower than the actual transfer price.

Nevertheless, clubs regularly use it to talk up the value of their players. For example, Olympique Marseille chairman Jacques-Henri Eyraud said in a 2018 press conference: ‘The first stage of our recovery is complete […] today, the club is competitive again. We invested €120 million during the last transfer period, and according to Transfermarkt our players are worth around €200 million.’

Marseille are not the only club doing this. The annual reports of Olympique Lyonnais, FC Schalke 04, Hertha BSC, TSG 1899 Hoffenheim and FC Porto all cite Transfermarkt as a source for the ‘value’ of their first team. And European football association UEFA uses Transfermarkt data in a 2016 report.

In doing so, these clubs create a reality that exists only on paper. Our data analysis shows that virtually no club is able to turn this theoretical value into actual income. In Europe's top leagues, between 62 and 70 percent of players earn them nothing; in the Netherlands, the figure is as high as 81 percent. This is the case when players serve out their contracts, are exchanged, or stop playing football. In the five top European leagues this summer, players in these three categories were shown on Transfermarkt as being worth more than €930 million.

‘We got a message that Ronaldo had blocked us. He disagreed with our valuation of his worth.’

Bart Tamsyn, Transfermarkt’s regional manager for the Netherlands and Belgium, says he thinks clubs, brokers, players and journalists put a lot of faith in the website. ‘When I just started as regional manager, I was overwhelmed by the amount of attention Transfermarkt attracts. I constantly receive emails from professional players and agents. Just recently, a regular player at SC Heerenveen asked if I could check his statistics.’

Even Juventus star Cristiano Ronaldo is not immune, says Tamsyn: 'Last year Ronaldo was downgraded, and his market value fell below €100 million. We put that on Instagram, and then we got a message that Ronaldo had blocked us. He disagreed with the price we’d put on him.’

Tamsyn says he and his fellow regional managers are sometimes offered dinners or watches in return for a better valuation, but that these offers just elicit laughter.

Thijs van Es, managing director of FC Utrecht, says that his club sometimes looks at the market values on Transfermarkt. Van Es calls them a baseline, rather than a major basis for decisions. ‘Setting prices in advance is complex. Many factors determine a transfer value, and each player is unique. We’re guided by the knowledge and experience of our technical staff, not from online sources such as Transfermarkt.’

‘I use Transfermarkt to look at the data of players that I might want to bring in,’ says Guido Albers. He is managing director of the agency Players United, which among others represents Dutch internationals Donny van de Beek and Steven Berghuis. Albers says the site’s figures are of secondary importance, though they’re often really close to the actual market values. He says that the rule of thumb among sports agents is one of supply and demand: the more interest, the higher the price. ‘Just like the housing market. A player is a product, harsh though it may sound.’

Back in Höhenkirchen-Siegertsbrunn, Martin Freundl closes his laptop. Outside, a plastic-wrapped Christmas tree is waiting to be decorated before the children arrive. Freundl has spent the past few weeks working on his Excel files: it’s almost the winter break, the time when Transfermarkt publishes an update of its market value estimates.

The work was more difficult this time. Covid-19 isn’t making anyone’s life easier, not even that of a Transfermarkt godfather. Some days, Freundl spent so much time on his laptop that it drove his wife mad. ‘Are you working on those statistics again,’ she would sigh.

The new figures are scheduled to appear a few days after our visit. After that, the phone of point-of-contact Christian Schwarz will be ringing non stop. ‘Technical directors of Bundesliga clubs, who will want to discuss the numbers with us,’ Freundl says.