The absence of fans did not cause footballers to doubt themselves but did make referees think twice, a study of behind-closed-doors football has found.
According to researchers from Reading University, playing matches without supporters had a minimal effect on the phenomenon of home advantage but it did correspond with officials showing fewer yellow cards to away teams.
In a paper on the effects of behind-closed-doors matches, researchers studied 6,481 games from before and after coronavirus lockdown. In the Premier League and Championship, games played in empty stadiums saw the proportion of home victories drop from 43.4% before the pandemic to 42.0%.
This small fall is similar to results in many other leagues that restarted behind closed doors. After apparently seeing a substantial drop in home advantage during early matches, the Bundesliga ended the season with the prospect of a home win having fallen from 40.8% to 39.2%. A similar pattern was observed in Spain, and home advantage increased in Italy: from 42.9% to 43.1%.
“While we saw some loss of home advantage in the early matches, things reverted in last few weeks,” said Dr James Reade, who conducted the research. “Maybe it’s all about familiarity.”
The effect of a crowd on sporting performance is a longstanding area of research. The obvious explanation for home advantage has always been that a crowd gees on its team and intimidates opponents. Other arguments include familiarity with surroundings and the possibility of fatigue in a travelling team.
“It’s hard to imagine that fatigue is too much of a factor any more, especially not in elite sport,” Reade says. With the absence of fans not affecting results much either, that leaves familiarity. “Results changed to begin with when players stepped out into their empty stadium, but that stopped as people got used to it.”
Dr Reade and his colleague Carl Singleton did, however, find that the absence of the crowd tallied with a drop in yellow cards given to away teams. In England the study observed that the number awarded to all players fell during the restart, but that on average away teams received half a yellow card less than before lockdown.