LOCKDOWNS WERE particularly frustrating for football devotees, who had no live matches to watch while stuck at home. But the fans most pleased by the sport’s return may be statisticians. For them, empty stadiums are not a cheerless last resort, but rather a chance to tackle a great quandary: why do travelling teams tend to lose?
Most studies have blamed referees for trying to placate fans. In one experiment, officials were shown recorded games and asked how they would have ruled. They were kinder to home sides when they could hear baying fans than when the sound was muted. Some analyses of live matches have found more bias with denser crowds. Before this summer, few competitive fixtures were played without fans. One study from this May found just 160 cases since 2002. In this small sample, the home team’s edge vanished. Referees gave similar numbers of cards for fouls to both sides, and visitors won almost as often as hosts did.
This finding could easily be skewed by a few clumsy tackles or flukey goals. But the pandemic has made a larger study possible. At our request 21st Club, a consultancy, has analysed 1,534 matches played without fans this year, spanning dozens of leagues.
Sure enough, officials no longer appear biased. Although the pattern varies widely by league, the total share of cards received by home teams has risen from 46% before lockdowns to 50% afterwards.
However, the lack of help from referees has merely reduced home sides’ advantage, rather than eliminating it. Football leagues give teams three points for a win, one for a draw and none for a loss. With crowds watching, home teams gained 58% of points; without them, hosts have still earned 56%. In other words, three-quarters of home overperformance remains intact.
So why have teams fared better at home, even without biased officials? Since May, hosts have taken 53% of shots at goal—less than the 55% they took in full stadiums, but enough to give them an edge.
The cause of this gap remains mysterious. In American sports, visitors have to endure long trips between games. But travel times within European countries rarely exceed a few hours. A more plausible reason is that coaches still use conservative line-ups and strategies when playing away, even though hostile officials no longer undermine their best players’ efforts. If that is a factor, managers who excoriate referees ought to consider their own failings, too. ■
Sources: 21st Club
This article appeared in the Graphic detail section of the print edition under the headline "Home comforts"
By The Economist https://www.economist.com/graphic-detail/2020/07/25/empty-stadiums-have-shrunk-football-teams-home-advantage