The absence of fans removes the home advantage associated with penalties called by National Hockey League referees.

The COVID-19 pandemic has had a major impact on professional sports, notably, forcing the National Hockey League to hold its 2020 playoffs in empty arenas. This provided an unprecedented opportunity to study how crowds may influence penalties awarded by referees in an ecological context. Using data from playoff games played during the COVID-19 pandemic and the previous 5 years (n = 547), we estimate the number of penalties called by referees depending on whether or not spectators were present. The results show an interaction between a team's status (home; away) and the presence or absence of crowds. Post-hoc analyses reveal that referees awarded significantly more penalties to the away team compared to the home team when there is a crowd present. However, when there are no spectators, the number of penalties awarded to the away and home teams are not significantly different. In order to generalize these results, we took advantage of the extension of the pandemic and the unusual game setting it provided to observe the behavior of referees during the 2020-2021 regular season. Again, using data from the National Hockey League (n = 1639), but also expanding our sample to include Canadian Hockey League games (n = 1709), we also find that the advantage given to the home team by referees when in front of a crowd fades in the absence of spectators. These findings provide new evidence suggesting that social pressure does have an impact on referees' decision-making, thus contributing to explain the phenomenon of home advantage in professional ice hockey.

Team-to-team transmission of COVID-19 in ice hockey games - a case series of players in Finnish ice hockey leagues.

BACKGROUND: The COVID-19 pandemic suspended nearly all team sports globally. The pro series have resumed playing by creating safe bubbles or massive testing protocols. Amateur level sports have also restarted seasons without possibility for such precautions. Our aim was to report the epidemiology of COVID-19 in an amateur ice hockey team and the team-to-team transmission during two games. METHODS: A descriptive brief report based on public statements by the local health authorities and the teams involved. RESULTS: An asymptomatic carrier of COVID-19 in a U-20 ice hockey team infected 22 of 28 team mates. The day before the first players had symptoms, the team had returned from a two games away trip. A few days later COVID-19 was detected in both opposing teams and they were ordered to quarantine. During the two weeks quarantine a total of 24 players from the two opposing teams tested positive. Some of these players were training with senior teams and three additional infected players were detected in two senior teams. In total, 49 infections were detected in five ice hockey teams, and six teams were in quarantine for two weeks. CONCLUSION: An asymptomatic player can potentially endanger the whole season of a team and put opponents in danger as well. We report massive team-to-team transmission of COVID-19 in the U-20 Finnish National Hockey League. In order to prevent spread of COVID-19 in amateur-level team sports, suitable protocols should be established and adopted into daily use.