Suporte social e vantagem da casa no futebol: o caso dos dérbis durante a pandemia COVID-19

Abstract

Home advantage (HA) is an intriguing topic in the sports context. According to this phenomenon, there is a competitive advantage of the home team in the contest. Factors such as social support, travel effects and fatigue of the visitor, familiarity with the environment and atmosphere of the competition, and referee bias are modulating points of effect already evidenced. Thus, the aim of the present study was to evaluate the HA rate of the world's major national football leagues during the pre- and during COVID-19 eras, especially of the derby-type matches of those clubs sharing the same stadium. After exploratory phase, data from 17 men's national football leagues were included, totaling 16,082 matches from 379 distinct clubs, with 223 derby-type matches in the "pre-pandemic" era and 191 matches in the "era during pandemic". HA was observed in most of the leagues analyzed, independent of the strata under analysis. There was ~8.4% reduction in the overall comparison of HA rate in the COVID-19 era with moderate magnitude of effect size (v Wilcoxon = 442, p= 0.012; r= 0.49, 95% CI [0.14, 0.72]). Dunn's post-hoc test with Bonferroni correction revealed a significant reduction in the HA rate (~-12.2%), with a large magnitude of effect size, in the context of derby games with shared stadiums and played without fans as a function of COVID-19 compared to derby games with fans ( = 3.738, p<0.001; r= 0.67, 95%CI [0.40, 0.81]). From another point of analysis, the HA rate of derbies obtained during the COVID-19 era corresponds to only 8.2% of the HA rate in that of derbies in the pre-COVID-19 era. Thus, our results demonstrate the decrease in the HA rate in the pandemic era, a decrease that seems to have been of greater magnitude in the same-stadium derbies. Future studies may elucidate psychological issues regarding the effectiveness of social support on the sports performance of home teams, and modulated losses on visitors and referees, especially in those cases that involve local derbies and fierce rivalry matches.