Abstract
In sport, relative age effects (RAE) occur when there is an over-representation of athletes born early in a selection year, as compared to relatively younger athletes who are born later in the selection year. It has been posited that slight age differences within a one-year cohort lead to performance and participation advantages, typically based on physical development (Wattie, Cobley, & Baker, 2008). Recently, Hockey Canada prohibited body checking in the 9- and 10-year-old age division (Atom), which allowed us to examine how reduced physicality within the sport might alter the RAE. The purpose of the study was to investigate the RAE of athletes who played with, or without, the body checking rule by inspecting the birth rate distributions of Atom players. Separate analyses for a cross-sectional and a quasi-longitudinal dataset demonstrated significant RAEs in both samples regardless of whether body checking was permitted. Inspection of effect sizes and standardized residuals revealed slight decreases in the strength of the RAE when body checking was not permitted, though this was limited to the second and third birth quartiles. Furthermore, it appeared that the changes in RAEs were most prevalent at lower levels of competition. Results indicate that the physical nature of a sport might, in fact, impact the RAE. Discussion focuses on implications the results have for sport scientists examining moderating factors of the RAE.Acknowledgments: We would like to acknowledge the Ontario Hockey Federation for their assistance with the current study.