When Simon Wilson first arrived at Southampton football club he was a consultant for a technology startup called Prozone. Prozone had developed a proprietary player-tracking software which, fed by eight cameras around the pitch, would output a two-dimensional bird’s-eye animation of a football match. The machine could track each player’s movement every 0.1 seconds, registering an average of 3,000 touches of the ball per game, and provide an answer to a range of statistical questions. Southampton adopted Prozone and later hired Wilson to work as a performance analyst for the first-team manager.
“Prozone wasn’t part of the culture of the game and most managers weren’t used to it,” Wilson says. “I was naïve but I couldn’t understand why they didn’t want this kind of information.” Once, just before an August 2005 football league Championship game between Luton Town and Southampton, Wilson gave a pre-match briefing to the team and the manager, at the time, Harry Redknapp. “Harry was more intuitive than analytical,” says Wilson. “He was nervous about overloading the players with information.”
Southampton lost 3-2. On the team bus, Redknapp turned to Wilson and said, “I’ll tell you what, next week, why don’t we get your computer to play against their computer and see who wins?”
Some managers, however, did get it – and one in particular was Clive Woodward. He had been the coach of England’s World Cup-winning rugby team in 2003, and in 2005 had been offered a one-year contract to serve as Southampton’s director of football. He had been the first coach to adapt Prozone to rugby, installing it at Twickenham four years before the World Cup, which allowed him to collect data on how England and its opponents played.
“When I first saw it I was fascinated because I’d never seen a game where you’re looking down and just see dots and data and movement,” Woodward says. “It removed a lot of the preconceived notions we had about how other teams played. It made a big difference when we started to see them as data, as opposed to teams we had never beaten before.” Once, after his players insisted that there was no space on the field to run into, Woodward took a printout of a Prozone freeze-frame taken 24 seconds into a match against France. It showed both teams around the ball in a small area on the pitch and acres of unoccupied space everywhere else. He stuck it on board with the message: “The space is the green stuff”. “Clive would challenge me at every level,” says Wilson about Woodward’s time at Southampton. “He would ask questions about every aspect of the game: why do we spend so much time working out how to score goals and not how to stop them? I would try to explain to him what they’re doing and he’d just keep asking why.”
Woodward and Wilson tried things such as filming players striking the ball, to study technique from a biomechanical perspective. Those initiatives, however, never had much impact. Redknapp left before the end of the year and Woodward departed at the end of his contract. Wilson had left the club shortly before Woodward, convinced that there was a better way of running a club. “Woodward believed that evidence, be it video or statistics or any kind of data, was fundamental to how you prepare a team,” Wilson says.
Woodward remains his biggest influence. “He taught me that we didn’t have to do things just because they had always been done in a certain way.”
Today, 19 of the 20 Premier League teams use Prozone. Each has its own team of performance analysts and data scientists looking for the indicators that quantify player performance, the events that determine matches and trends that characterise seasons.
They are scientists dissecting the world’s most popular game, looking at data from Prozone and other sources to understand what dictates the difference between winning and losing. In the environment of the multimillion-pound Premier League, clubs don’t just want a competitive advantage, they need it.