The Wisdom of the Crowd

Conspicuous consumption runs through soccer’s billion-dollar transfer market. Club executives hold meetings in deluxe suites in the finest hotels in London, Monte Carlo and Milan: the Connaught, the Méridien, the Palazzo Parigi. There, they haggle with agents in tailored suits over eye-watering transfer fees, lavish salaries and towering commissions.

The players being traded sink into the plush leather seats of private jets to travel between clubs, before signing contracts worth tens of millions of dollars in sumptuous, state-of-the-art training facilities.

Many of the numbers that make that world go around, though — the vast sums that change hands in exchange for a player, the fees due to an agent, the money that will make an athlete rich — can be traced back to a place far removed from all that glamour and wealth: an unremarkable office building on a quiet, suburban street in Hamburg, Germany.

The figures decided there are regularly cited, uncontested, by the news media. They are quoted by club presidents and chief executives. An investigation by the Dutch website Follow the Money found that several teams in Europe used them in their official financial filings or in prospectuses sent out to potential investors. They have even formed the bases for legal proceedings; in one recent case, almost a million dollars rested on their accuracy.

They come from the website Transfermarkt, and the office building it calls home may seem a world away from the public image of the industry that it covers. In reality, it is at the very heart of it.

To describe a website is, invariably, to undersell it. Reddit is just a place where people talk about things. Instagram is where they upload pictures of their breakfasts. Pinterest is where you imagine what you would like your bathroom to look like.

Boiled down, Transfermarkt is equally underwhelming: It is a site where people go to find, and discuss, information about soccer players. Some of it is basic — dates of birth, ages, previous clubs. Some of it is a little more advanced: It can tell you which position Lionel Messi occupied in each of his games for Barcelona last season, for example, and how many of the goals scored by his new team, Paris St.-Germain, involved Kylian Mbappé.

The French team Bordeaux cited Transfermarkt’s valuations of its players in a sales brochure. Credit…Romain Perrocheau/Agence France-Presse — Getty Images

More impressive, it can provide that same level of detail for some 840,000 of their professional colleagues around the world. Transfermarkt’s data extends from the bright lights of England’s Premier League all the way to the top flight in Mozambique. Its data runs way beyond players, too, by offering information on more than 100,000 managers and coaches and scouts and agents. Transfermarkt can, in some cases, tell you who drives a team’s bus.

This is what the site was designed to do: provide a source of knowledge, a point of reference and, through its humming chat boards, a place for a community of like-minded (read: slightly nerdy) individuals to gather. But that is not what it is known for, not what has made it famous.

Trying to place a specific worth on an individual soccer player is like capturing the beauty of a sunrise. The sport’s frenzied trading business is, in the words of Thomas Lintz, Transfermarkt’s managing director, a “marketplace without many of the classical market factors.” A player might be priceless to one club and worthless to another. Values can soar or tumble based on a manager’s whim, a poor game or the emergence of a superior rival.

Still, for years, Transfermarkt has been trying to provide a guideline of roughly how much every individual player might cost, all the way from Messi to Mozambique, through what it calls its Market Values: an estimate of worth based on the work of thousands of volunteers and sifted by the site’s 80 staff members.

It is that single detail — what is, deep down, just a crowdsourced guess at a valuation — that has transformed Transfermarkt from a single point of light in soccer’s great digital constellation into something approaching a lodestar, that has turned it, inexorably, from a site designed to reflect the sport’s ever-bubbling transfer scene into one that, now, defines it.

Community

The journey from Bremen to Hamburg takes a little more than an hour. At the turn of the century, it felt much farther to Matthias Seidel. An advertising executive and ardent fan of Werder Bremen, his local team, Seidel had moved to Hamburg, Germany’s media capital, for work.

Keeping up with his beloved Werder’s fortunes, though, proved almost impossible. The internet was still in its infancy as a news resource. Hamburg’s press contained barely a mention of all the transfer gossip that had been covered so comprehensively in Bremen’s newspapers.

Seidel decided to take on the job himself. He set up a website, initially designed to keep track of the players Werder had been linked with signing, either in the local or national news media. It was rudimentary: He entered their names onto a spreadsheet, added whatever scant details he could establish, and published.

Soon, he found strangers getting in touch with him to highlight mistakes, suggesting that he had incorrectly labeled central midfielders as wingers, or pointing out that certain players had recently celebrated birthdays. He started issuing correction forms, so that users could submit updates.

“These were the early days of internet communities,” Lintz said. Slowly, and organically, one coalesced around Transfermarkt, consisting largely of fans with a taste for rumors and a vague interest in statistics. “The correction forms were really key,” Lintz said. “You had to register to submit a correction, which then went into our system. Users entered a lot of corrections, and they were accepted.”

Seidel also started building spreadsheets for other teams. After a while, he decided to branch out, adding disciplinary records and club colors to his site’s pages. When he wanted to know which agents represented which players, he acquired a stack of copies of Kicker, the German soccer magazine, and trawled through thousands of pages underlining every mention of an agent before entering it into his system.

The website he created, Transfermarkt, would become a cornerstone of soccer’s digital age. But its origins — as a Werder Bremen fan site — were distinctly analog.

“At the time, there was just a little community interested in Italian football, and only Serie A was part of the database,” said Jatin Dietl, now the site’s area manager for Italian soccer, “but it was enough to keep me there. It was the mix of the database, the community and the fact that you could be a part of all of it.”

Lintz identifies the World Cup of 2006, held in Germany, as the point at which Transfermarkt’s steady trajectory went exponential. (He does not have a definitive explanation for why that might be, but it seems a reasonable guess that people in Germany were suddenly searching for information on players they had not previously encountered.)

Everything moved quickly after that. A year later, the German publishing giant Axel Springer bought a majority stake in the site. In 2009, it started to expand its offerings, starting with the players and teams and leagues in Austria and Switzerland — “we did not need to translate anything,” Lintz said — and then moving into England, Italy and Turkey, the markets that provided most of Transfermarkt’s traffic.

More than a decade later, it has sites serving 22 countries. It has recently opened domains in Argentina, Malaysia and Mexico. Lintz now has 80 staff members, including not only those who update the player information and moderate the discussion boards but a team of journalists, too. The number of “data scouts,” the volunteers who feed information into the site, runs into the hundreds.

Its reach has grown as well. In one month this year, Transfermarkt’s various sites attracted 39 million unique users and 672 million page views, from Azerbaijan to Zimbabwe. It has somewhere in the region of 680,000 registered users (though Lintz said only about 50,000 were considered active members, regularly contributing updates on players or commenting on message boards).

To most of those users, the site’s mix of statistics, community and enthusiasm explains its metamorphosis from the passion project of a disenfranchised Werder Bremen fan into viable, million-dollar business.

To a specific subset, though, what appeals is something else. Transfermarkt is not just an institution for a certain stripe of fan; it has become, too, part of the fabric of soccer. “Everyone has the app on their phone, whether it’s scouts or agents or executives,” as one executive put it. “And everyone has it open.”

Its appeal is rooted, in part, in the basic information it offers: the length of a player’s contract, his injury history (the site does not currently have a database for women’s soccer) and the name of his agent. It is a quick, easy piece of due diligence.

But what they are really interested in is the metric that has become Transfermarkt’s calling card, what it calls Market Value. To the site and its staff, that figure is only a best guess at a player’s worth. To those working in soccer, though, it is something more concrete, more precious: a fact.

Value Is Volatile

Twice a year — once before each of European soccer’s transfer windows, in January and high summer — Transfermarkt’s staff and volunteers begin the painstaking process of reassessing the transfer value of each of the 800,000 players in the site’s database.

Users will discuss the worth of a player, suggesting it should move up or down, based on a variety of factors: a string of good performances, a problem with an injury, a similar player’s moving for a higher or a lower fee than expected and thus shifting the market. A few wander deep into the weeds.

“Someone will point out that this player has won a higher percentage of headed duels than another player, so should be worth a little more,” Lintz said. Only those with supporting evidence are taken into consideration by the ultimate arbiters of worth: each country’s area manager, and eventually Christian Schwarz, who oversees all market values on the site.

But while the arguments are all considered, detailed and informed, and while the decisions are checked and crosschecked, the system is — ultimately — human. “There is no algorithm or spreadsheet,” Lintz said. “It is a qualitative approach. We weigh arguments, meet with our moderators, find a compromise.”

The system has been refined over the years. “It is too easy to say that we gather many users telling us their opinions and, just like that, we have the perfect market value,” Dietl said. “It is the mix of user input and our experience that makes the figures so good.”

Lintz and his colleagues are proud of how accurate their educated guesses tend to be. They take it as vindication and validation of their “wisdom of the crowd” approach when a real-life player moves for a fee similar to his value on the site.

But they know, too, that there is a reason for that. Though Transfermarkt started out as — and is still, at heart, designed to be — an attempt to reflect the state of the transfer market, it has come to exert a gravity on it. A player’s worth on Transfermarkt is not seen within the sport as an estimation, but, effectively, as a price tag: the starting point for negotiations on trades in which tens of millions of dollars change hands, a digital anchor for a real-world fee.

Transfermarkt’s staff members said they were sometimes contacted by clubs seeking to correct the fees — often never made public — they had paid for players. More often, agents, families and even players themselves get in touch. “In the lower leagues, having a good Transfermarkt profile seems to be quite important to find a good club,” Dietl said. “So people contact us about missing data or adding photos.”

Most of the time, though, their “intentions are clear,” Tobias Blaseio, the site’s area manager for Spain, said: “They want to influence their market values.”

That these figures mean enough to be worth trying to massage is, of course, testament to how good Transfermarkt is at estimating the value of players. The problem is that those working inside soccer’s billion-dollar transfer business are not always as rational.

Everybody wants to know what a single player is worth but, deep down, that value is entirely subjective. And it changes almost every day, raised and buckled by tectonic shifts that nobody can control.

In that environment, it is natural that the people whose jobs rest on being able to find — or at least establish — value should seek some way of dampening that volatility, of identifying some sort of signal in the noise.

Transfermarkt did not intend to provide it. But, as Lintz said, “a lot of the people in soccer are not professionals, like surgeons.” They, too, are simply making their best guesses. And in that sort of environment, it is easy to confuse an estimate with a fact, to listen to the wisdom of the crowd, and to interpret it as truth.