While football players sweat it out on the field, their supporters in the stadium shout and sing, giving those playing at home an advantage. When Covid-19 hit, some expected that home advantage to disappear when spectators had to watch games on screens – but research suggests home teams retain a statistical advantage over their visitors.
Researchers have long investigated the home advantage phenomenon – implicating crowd support, referee bias, psychological effects of expectations, travel fatigue, familiarity, territoriality, and tactical behaviour as factors, but there is no consensus on which are the main drivers.
The bans on spectators during Covid offered scientists an ideal opportunity to measure the impact of crowd support and so researchers have compared more than 1,000 professional matches played without spectators and more than 35,000 matches with a crowd across 10 professional leagues, including Spain, England and Germany during the seasons 2010-11 to 2019-20.
In the study, researchers explored the impact of spectators on four broad categories, including home advantage (measured by the number of goals and points scored) and disciplinary sanctions (measured by fouls, yellow cards and red cards). Without the thousands of home supporters, home advantage fell by about a third but the drop was not statistically significant, they found.
Prof Matthias Weigelt of Paderborn University, an author of the study – who is a season ticket holder at Arminia Bielefeld, a team in the German Bundesliga – said he was surprised by the findings.
“I was always convinced that me being at the games and supporting the team, at least changed something, sometimes. But what can you do? It is science and the large data set of more than 40,000 games, which were considered for the study, cannot be ignored. Social support does not seem to be a key factor for the home field advantage.”
Under normal circumstances home teams receive fewer disciplinary sanctions and are able to create more offensive actions compared with away teams. But, in line with previous research, the authors found the difference in disciplinary sanctions disappeared – or was even slightly reversed – when the crowd was absent, suggesting spectator presence was likely to be the only or predominant reason for biased referee behaviour, they wrote in the journal Plos One.
“If a team asked me what to do to gain an advantage, I would need to tell them to put as much social pressure on the referee as possible. The problem is that that’s not fair play, so I don’t really want to say that – although I think it’s true and that’s what’s in this study,” said the lead author, Fabian Wunderlich of German Sport University Cologne, cautioning that it was still unclear what the main drivers of home advantage are and that VAR (video assistance for referees) was not accounted for in the analysis.
Thomas Peeters, who runs the Erasmus Center for Applied Sports Economics in the Netherlands, said that given not all the games in the 2019-20 season were played behind closed doors, the study (alongside other recently published studies) may not accurately capture the true impact of the crowd on home advantage.
The spectator-less 2019-20 games used in the research were also towards the end of the season, a period usually seen as a make-or-break time for teams hoping to finish the season strongly and qualify for European football. A better experiment would have been to use data from the 2020-21 season, he said.
Home advantage is not really a problem in a round robin tournament such as the English Premier League where home advantage is exchanged – it is tournaments like the FA Cup when you play only one game at someone’s ground when it is problematic, he added.
“Generally, home teams sell the tickets to home fans and home fans are pretty happy when they win,” he said. “So, increasing the chance of that happening might not be such a big problem … give the customer what the customer wants.”