Born to Win? The Hidden Bias of Birthdates in Spanish Orienteering Talent Selection

Abstract

The Relative Age Effect (RAE) refers to the advantage that relatively older athletes within the same age group may have in sports. While this phenomenon has been widely documented in numerous disciplines, its presence in orienteering remains largely unexplored. This study aimed to analyse the existence of RAE among Spanish orienteers selected for international competitions organised by the International Orienteering Federation (IOF) between 1987 and 2023. A total of 384 participations (225 male, 159 female) were examined across the European Youth Orienteering Championships (EYOC), Junior World Orienteering Championships (JWOC), and the European and World Orienteering Championships (EOC + WOC). The distribution of birth dates by quartiles and semesters was compared using chi-square tests, Cramér’s V, Z-tests, and odds ratios with 95% confidence intervals. The results revealed a significant RAE in male athletes, particularly in JWOC, where those born in the first quartile were up to 3.77 times more likely to be selected than those in the third quartile. In contrast, no significant associations were found in female athletes, which may reflect structural or developmental differences related to sex. These gender-based disparities highlight the importance of integrating sex-specific considerations into selection policies. Overall, the findings suggest a selection bias favouring relatively older males, which may hinder the development of late-born talent. Therefore, it is recommended that selection criteria be reassessed to ensure fairer and more inclusive talent identification and development in youth and elite orienteering.