Hockey success and birth date: The relative age effect revisited

In a replication of studies by Barnsley et al. (1985), and Grondin et al. (1984) the authors gathered birthdates of players in the National Hockey League (NHL), Western Hockey League (WHL), Ontario Hockey League (OHL), and Quebec Major Junior Hockey League (QMJHL). The players were categorized according to month of birth. Additionally, the players were categorized by country of birth, reflecting the changes in professional hockey over the period since the original studies. The results indicate that despite the globalization of hockey and changes in minor hockey, relative age effect, that is, a strong linear relationship between the month of birth (from January to December) and the proportion of players in the leagues studied, still exists.