The influence of removing home advantage on the Chinese Football Super League.

BACKGROUND: Due to the COVID-19 pandemic, the 2020 season Chinese Super League (CSL) was held in neutral venues, this study aims to analyse the impact of removing home advantage (HA) in CSL. METHOD: 240 games of the CSL 2019 season (home and away double round-robin system) and 160 games of the 2020 season (in neutral venues) were analysed. 27 technical and tactical performance indicators were involved as dependent variables. A multiple linear regression model was established to analyse the influence of removing HA on the performance indicators. RESULTS: After moving from home stadium to neutral venue in 2020 season, goal, shot, shot on target, shot from outside box, shot from inside box, shot on target from inside box, corner kick, key pass, cross, breakthrough, tackle decreased significantly (p < 0.05), while yellow card and foul increased steeply (p < 0.05). Comparing with playing away match, in neutral venue, free kicks and pass accuracy enhanced radically (p < 0.05), while tackle, clearance and block shot dropped noticeably (p < 0.05). CONCLUSION: When removing HA and playing in the neutral venue, teams' performance dropped significantly. This study confirmed the positive impact of HA on the teams' performance and may help elite football teams make proper playing strategies regarding different match locations.

Effect of tournament format change on team performance of Chinese Football Super League during COVID-19 pandemic

The outbreak of COVID-19 forced Chinese Football Association to adopt a special format for the 2020 Chinese Football Super League (CSL) after 5-month suspension. All 160 matches (decreased from 240) were divided into two stages (round robin;two-legged knockout) and played behind closed doors in two neutral cities (Suzhou and Dalian). The purpose of this study was to investigate the influence of absence of spectators and format change on teams' winning percentage and match performance. Technical-tactical and event data of all 400 matches during 2019 and 2020 seasons played by 18 teams were collected. A total of 26 performance indicators were extracted and standardized from the original data. The independent t-test results showed that there were statistically significant differences in 13 performance indicators between 2019 season home win and 2020 season win: shot, shot not on target, simple pass, pass, pass accurate, key pass, corner, corner accurate, dribble and take on (p<0.025, absolute ES: 0.28-0.74) for player performance as well as defensive fouls, defensive third foul and yellow cards for referee decision-making (p=0.001, absolute ES: 0.42-0.45). And there were statistically significant differences in 16 performance indicators between 2019 season home not win and 2020 season not win: shot, shot not on target, touch, simple pass, pass, pass accurate, key pass, corner, corner accurate, dribble, defensive duel, penalty shot and clearance for player performance (p<0.04, absolute ES: 0.21-0.93) as well as defensive third foul, defensive foul and yellow card for referee decision-making (p<0.015, absolute ES: 0.29-0.43). The findings implied that the change of match locations and absence of team supporters led to a decrease in teams' match performance and an increase in referees' decision. Although top-ranked teams seemed to be unaffected and the low-ranked teams showed an increase in winning percentage, the fairness of such tournament format needs to be reconsidered.

Did the Absence of Crowd Support During the Covid-19 Pandemic Affect the Home Advantage in Brazilian Elite Soccer?

This study aimed to investigate the impact of crowd absence due to the COVID-19 pandemic on home advantage in Series A and B of professional Brazilian male soccer. Moreover, we sought to compare the home advantage between different competitive levels. Data from 2018 to 2020 Brazilian professional soccer championships (Series A and B) were analyzed, consisting of 2280 matches. The effect of home advantage was calculated in relation to the number of points won, the number of wins, goals scored and goals conceded. Our results indicated that home advantage was reduced in Serie A. Specifically, the 2020 (absence of the crowd) and 2019 seasons showed smaller home advantage compared to the 2018 season. On the other hand, Serie B analyses indicated no changes in home advantage over the seasons analyzed. The comparison of home advantage between competitive levels indicated higher home advantage in Serie A, exclusively in the 2018 season. In addition to the absence of fans, other changes occurred in elite sports due to the pandemic, such as changes in rules and the calendar. Considering that home advantage is affected by multiple interacting factors, it is important to investigate specific sports leagues across the world to determine which factors had the greatest impact on the advantage of playing home matches.

Professional football in times of COVID-19: did the home advantage effect disappear in European domestic leagues?

This study aimed to examine how the home advantage (HA) and home teams' performances changed in European football leagues (German Bundesliga, Spanish La Liga, English Premier League, Portuguese Primeira Liga and Italian Serie A) with the measures imposed by legal authorities to deal with the COVID-19 pandemic (no audience, five substitutions and "cooling breaks"). The HA (Pollard's rescaled method) and home performance-related statistics of matches contested before (n = 491) and after (n = 491) the 2019-2020 season break were calculated and compared, for each league and for all five, using the paired t-test or the Wilcoxon signed-rank test. Overall, the HA did not significantly decrease in European leagues (from 16.4% to 11.6%; trivial effect size [ES]); however, a one-sample t-test revealed that the HA after the COVID-19 break was significantly greater than 0% (small ES). While the HA completely disappeared in the Bundesliga (large ES), its effects remained stable in La Liga (small ES), Premier League and Primeira Liga (trivial ES), and even increased in Serie A (medium ES) after the return. Home teams' performances in these leagues were influenced to different extents by the COVID-19 situation, especially by playing behind closed doors. Altogether, significant decreases were observed for total shots, tackles (medium ES), shots on target and pass success (small ES). Therefore, the role of crowd support seems to vary depending on the context characteristics in which football is played. Also, the augmented "information transfer" from coaches to players during COVID-19 matches might have masked the crowd effects on the HA.