How stadiums emptied by COVID halved football's home ground advantage
The concept of a home ground advantage, where teams play in familiar surrounds in front of their own adoring fans, is broadly accepted as having a major bearing on match-day performance, but exactly how much benefit does it bring? To dig into this question, a new study has analyzed thousands of football matches that took place in empty stadiums Europe's top leagues last year, and found that the home team's success was indeed compromised, so much so that their advantage was almost halved.
As the pandemic took hold and ground many aspects of society to a halt last year, it presented scientists with some unique opportunities to study the effects of human behavior, and what happens when everybody is stuck at home. Last year, we learned how COVID-19 lockdowns halved human-related seismic vibrations across the globe, led to significant declines in air pollution, and even how that lack of pollution boosted the output of solar panels. So far as European football goes, the pandemic meant empty stadiums for much of the season.
“COVID-19 forced football at all levels to an unexpected halt just a quarter of the way through the 2019/2020 season," says lead author Dane McCarrick from the University of Leeds. “When it returned, the remainder of the games took place behind closed doors with no fans present. This provided an unintentional, and unique, opportunity to examine one of the most talked-about and empirically studied phenomena in professional team sport: the home advantage."
The scientists collected data on more than 4,800 games that took place in the English Premier League, the German Bundesliga, La Liga in Spain, the Italian Serie A and a host of other top-tier competitions spanning 11 countries. And their analysis tells an interesting story about what it meant to play host in the COVID-era.
With fans present, home teams scored an average of 0.29 goals more than away teams. With no fans in the seats, home teams scored an average of just 0.15 goals more than the visiting teams. With regards to their standings on the table, home teams playing in front of fans won 0.39 championship points per game than they did when playing away. With no fans in the stadium, home teams earned only 0.22 points more than they did when playing away.
This combination of fewer goals scored and fewer points earned per game amounts to an almost halving of the home ground advantage across Europe's top-flight leagues last year. And the researchers found the referees had a role to play.
The analysis showed that referees gave more fouls against the home team with no fans present, and dealt out far fewer yellow cards against visiting teams without screaming spectators to egg them on, while red cards followed a similar patten but less pronounced. The lack of fans appeared to have no bearing on fouls given out against the away team, however, nor the amount of yellow cards given to the home team despite an increase in their fouling.
To glean some insights into how the empty seats might affect a team's attacking prowess in a match, the scientists measured the number of corners won, shots taken and shots on target.
With no fans in the stadium, home teams won an average of 0.7 fewer corners per game, took 1.3 fewer shots at goal and had 0.4 fewer shots on target. Meanwhile, the empty stadiums had a negligible impact on the attacking of away teams, who earned only 0.10 more corners, took 0.17 more shots and had 0.2 more shots on target without a home crowd to contend with.
A common school of thought is that a home team enjoys an advantage when it comes to the referees because of the thousands of screaming supporters that might influence their decision-making. Interestingly, the authors found that the referee decision-making was much more heavily influenced by a team's dominance than it was the pressure of a passionate home crowd.
“When a team’s dominance over the game was included in the analysis, the associations were much weakened for fouls and yellow cards and, remarkably, become non-significant for red cards," says McCarrick. "This shows, for the first time, that the influence of home fans on referees mostly disappears when the style of play is taken into account.”
The study is just one of many exploring the home ground advantage phenomenon, some of which have offered up rather different findings. One study published earlier this year found only a "non-significant" decrease in home ground advantage with no crowds, though that particular study spanned a decade and doesn't offer the same compelling before-and-after snapshot of a COVID-inspired season of two halves.
“This is a really important investigation that contributes to the long-standing debate on the main reasons for the home advantage in sport – a worldwide phenomenon affecting team sports at all levels, from recreational to elite," says study author Dr Sandy Wolfson, from Northumbria University.
The research was published in the journal Psychology of Sport and Exercise.
Source: University of Leeds