Soccermatics, Mo Salah and Liverpool’s win
It was the former Liverpool manager Bill Shankly who spoke the immortal words, ‘Football is not a matter of life and death . . . It’s more important than that.’
— Sumpter, David. Soccermatics: Mathematical Adventures in the Beautiful Game
A great article from NYT on soccer analytics;
For these sorts of reasons, soccer was assumed to be unsuited to the analytical approach described in Michael Lewis’s 2003 book “Moneyball,” about how the Oakland A’s baseball team found an advantage by evaluating players using different criteria than everyone else. Soccer seemed impossible to quantify. Much of the game involves probing and assessing, moving the ball from player to player while waiting for an opening. And then the only goal might come from a winger who has done little else — after, say, a faulty clearance by a team that otherwise has been entirely dominant. “Our game is unpredictable,” says Sam Allardyce, who has managed 12 clubs over nearly three decades before Everton fired him last year. “Too unpredictable to make decisions on stats. We’re not talking about baseball or American football here.”
Chelsea created the Premier League’s first analytics department in 2008. Arsenal later bought a statistical analysis company, StatDNA. But the managers of those clubs didn’t see an advantage in applying data to the sport, or they were too busy trying to keep their jobs to figure out how to do it. A few years ago, the OptaPro analytics conference emerged in London as a way for the tiny band of soccer quants to present papers to one another. Still, all those charts with arrows and heat maps revealing where most of the action takes place seemed to have little effect on the game. As new metrics emerged, commentators and coaches took pride in repudiating them. When ESPN’s Craig Burley, a former Premier League midfielder, was asked on the air to comment about a team’s “expected goals,” a formula that calculates how often a team should have scored as opposed to how often it actually did, he replied with disbelief. “What an absolute load of nonsense that is,” he shouted. “I expect things at Christmas from Santa Claus, but they don’t come.”
But teams like Chelsea and Arsenal have resources at their disposal that allow them to accumulate the best talent. Compared with them, Liverpool was essentially in the position of those 1990s A’s teams. A different approach was necessary for it to keep up with them. And all those players running around the soccer field were clearly doing something. Every now and then, too, goals were scored. If collecting and analyzing data could help divine a connection, wasn’t it foolish not to try it?
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Graham recommended that Liverpool acquire Salah, who was thriving in Italy. In American sports, the team might have offered another player in exchange. In soccer, players’ rights are bought and sold in a worldwide marketplace. Once a sale price is reached, negotiations begin with the player. If he isn’t satisfied with the salary being proposed, or if he dislikes the city where the team plays or the manager he will play for, he can remain where he is. Grooming emerging talent and then selling the rights to it for a profit can help smaller teams stay solvent. Even some clubs playing in their countries’ top leagues, such as Germany’s Bayer Leverkusen, use the process to generate enough income to remain competitive. “Transfers are where the money is,” Graham said. “They are a huge component of financial performance.”
That July, Liverpool paid Roma about $41 million for Salah. Graham’s data suggested that Salah would pair especially well with Firmino, another of Liverpool’s strikers, who creates more expected goals from his passes than nearly anyone else in his position. That turned out to be the case. During the season that followed, 2017–18, Salah turned those expected goals into real ones. He broke the Premier League record by scoring 32 times. He also became the symbol of Liverpool’s revival. His crown of curly hair and infectious grin, and his stubby legs that somehow ate up ground as he raced across the turf, made him one of soccer’s most recognizable players. In what turned out to be a harbinger of this year’s progress, Liverpool made an unanticipated run to the final of last season’s Champions League. That provided the first tangible evidence that the strategies put in place by Henry and his Fenway group were working. This season, Salah was one of the three players who led the Premier League in goals. (His teammate Sadio Mané was another.) The website Transfermarkt, which tracks player valuations, estimates his current value at $173 million.
For Discussion: How do you think will the use of data science and analytics change the future of soccer? Comment also on David Epstein’s theory about ‘Roger versus Tiger path’ to sports stardom — listen to this podcast or read his book Range.
Clubs have consequently started their own research labs, mostly behind closed doors. Liverpool hired Ian Graham as Director of Research in 2012. With the help of a handful of highly qualified co-workers, he has been producing statistical models predicting the outcome of football matches and conducting performance analysis of players. He holds a PhD in physics from the University of Cambridge. Manchester City and FC Bayern have set up similar departments.
— Biermann, Christoph. Football Hackers
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