Analysis of the Relative Age Effect According to Player Positions in the UEFA Champions League and UEFA Europa League: A Descriptive Study

OpenAlex İngilizce

Objective: This study aimed to investigate the presence and magnitude of the Relative Age Effect (RAE) among professional soccer players included in the squads of teams participating in the Union of European Football Associations Champions League (UEFA CL) and Europa League (UEFA EL) during the 2023-2024 season. Additionally, it examined whether the distribution of players' birth quarters varied across leagues and playing positions. Material and Methods: The sample included 2,168 professional soccer players from 64 teams in the UEFA CL and UEFA EL group stages. Players' birthdates were categorized into four quartiles: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December). Data were manually collected from publicly available soccer statistics websites. A chi-square analysis was performed to examine birth quartile distributions across leagues and playing positions. Results: The study found a significant RAE, with 32.0% of players born in Q1 and only 19.4% in Q4. This pattern was consistent across both the UEFA CL and UEFA EL, indicating no significant difference between leagues. The distribution of birth quartiles did not significantly differ by playing positions (goalkeepers, defenders, midfielders, forwards). Conclusion: The findings demonstrate the persistent impact of RAE in elite European soccer, favoring players born earlier in the year. This bias is consistent across different leagues and positions, highlighting the need for equitable talent identification processes. Addressing RAE could enhance inclusivity and diversity in talent selection, ultimately improving the overall quality of professional soccer.