category (U10 to elite) in the year 2010 were evaluated. The year was divided into four quarters. (Q1: Jan. to Mar.; Q2: Apr. to June; Q3: July to Sept. and Q4 Oct.
Does date of birth influence performance of Swiss track and field athletes? Michael Romann, Louis Heyer & Jörg Fuchslocher Swiss Federal Institute of Sports Magglingen, Switzerland Keywords: birth date bias, talent identification, professional athletics Introduction Identifying talented athletes at an early age has become one of the major issues in many competitive sports. The relative age, which refers to the difference in age between children in the same selection year, has a significant influence in the talent identification process (Cobley, Baker, Wattie, & McKenna, 2009) (Cobley et al., 2010). The primary purpose of this study was to determine, if the date of birth influences performance of Swiss track and field athletes. Methods 840 female and 840 male athletes who achieved one of the best 30 results (Top 30) in their age category (U10 to elite) in the year 2010 were evaluated. The year was divided into four quarters (Q1: Jan. to Mar.; Q2: Apr. to June; Q3: July to Sept. and Q4 Oct. to Dec.). The percentage of athletes born in the respective quartiles was compared to the distribution of all registered members (RM) in the federation and to all respective births in Switzerland (BP). Sprint, middle-distance, long jump and javelin throw performance were examined for each age group. Statistical comparisons were calculated using chi2-tests. Results Relative age effects (RAEs) were found with a distribution of Q1=38.2%, Q2=26.3%, Q3=20.0%, Q4=15.5% for female and Q1=42.5%, Q2=30.8%, Q3=16.5%, Q4=10.2% for male athletes. The month of birth distribution differed significantly from the BP and the RM for the respective years in both groups (p
