The Impact of Cheering on Sports Performance: Comparison of Serie A Statistics Before and During COVID-19.

Background:  The role of cheering in home advantage in sports performance is unclear. As anti-coronavirus disease 2019 (COVID-19) restrictive measures have prevented crowds from entering stadiums, analysis of the past two football seasons can reveal important details.

Objective:  This paper aims to compare the last two football seasons in Italy with the previous six, highlighting changes due to the absence of cheering.

Methods:  We compared the average percentages of points obtained in home matches from 2013 to 2019 with those in the timelapse 2019-2021. The same operation was performed with referee statistics, such as fouls, penalties, and cards awarded against home teams. To do this, we used Welch's t-test and percentage increases. Pearson and Spearman's correlations were searched between the percentages of points collected in home matches and total points earned from 2013 to 2021.

Results: The average percentage of points collected by teams in home matches dropped by 8% (Welch's t = -4.3). The negative correlations between home collected points and total points in 2013-2019 timelapse have significantly diminished during the last two seasons (Welch's t = 6.2), approaching zero. Penalties against home teams have increased by 30% (Welch's t = 2.6), reaching 51.4%.

Conclusions:  This research provides statistical evidence supporting the crowd's impact on sports and refereeing performance in Serie A. However, our results also suggest that part of the home advantage is linked to factors independent of the audience. Future research can deepen the above phenomena from a theoretical-psychological point of view.