The end of game-week one in the 20/21 Premier League brought with it the 100th match behind closed doors (BCD). The change is stimulating a cottage industry of research papers analyzing the effects of fans not being present in stadia.
No doubt aggression is one area being explored. There was no sending’s off last weekend, albeit it was only an 8-match game-week – I say sending off as Kyle Walker-Peters was issued a red card but Jon Moss overturned his call, following consultation with VAR, and the Southampton player was reprieved. The challenge was downgraded to a yellow card. For the 15 EPL matches with fans present at Selhurst Park last season, Crystal Palace averaged a home attendance of 25,060 – would Moss have been influenced by them if they were present?
For the 100 matches BCD there has been 9 red cards issued. For the 100 EPL matches before this there was 13 red cards – not much of a difference. If we take all EPL matches for last season, prior to the restrictions, the average red card award ratio was 0.12.
There seems to be a small reduction in the number of red cards (I’m guessing not statistically significant). The change in yellow cards is another issue.
This minor decrease in reds might be related to the absence of fan pressure on referees. It may also be due to players not having a crowd to respond to. Maybe players are less aggressive towards opposition players when there is nobody present to rile them. There is another possible interaction; fans venting that motivates players to pressurize officials. If there are any aggression effects when more data becomes available, disentangling these direct and intermediary causes will be tricky.