Playing at empty stadiums had a hugely negative effect on the success of home teams, with home advantage almost halved, according to new research.

The study, Home advantage during the COVID-19 pandemic: Analyses of European football leagues, carried out by the University of Leeds and Northumbria University in the UK, looked into whether the home advantage at professional football (soccer) games applies when fans are not present.

The findings will be published in the September 2021 issue of Psychology of sport and Exercise and have been peer-reviewed online.

"Home advantage" is a widely-accepted phenomenon, describing the benefit that a sports team playing at their own venue enjoys over the visiting team. This is attributed to the effect of fans on the players or referee; playing in familiar surroundings and the effects of travel on the visiting team.

Researchers used data to asses at 4,844 games across 11 European countries, including the top two tiers in England, Germany, Spain and Italy, as well as the top divisions in Portugal, Greece, Turkey, Austria, Denmark, Russia and Switzerland.

They found that, with fans present, the teams won 0.39 points more per game at home than away. With fans absent, however, the advantage was almost halved as teams won only 0.22 points more at home than away.

With fans present, home teams scored 0.29 goals more per game than away teams, but without fans, home teams scored just 0.15 goals more than the visitors.

The research also suggests that the lack of crowds affected how referees judged fouls against home and away sides.

According to the data, referees gave more fouls against the home team and far fewer yellow cards against away teams in empty stadiums.

Lead author Dane McCarrick, from the University of Leeds' School of Psychology, said: "COVID-19 forced football at all levels to an unexpected halt just a quarter of the way through the 2019-20 season.

"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.

"This new knowledge reveals that in the most basic sense, fans attendance matters."

To read more about the study and access the full report, click here.