Relative age effects on the Brazilian women's soccer championship: influence of the age group, competitive division, and sports performance

This study aimed to analyze the existence of the relative age effect (RAE) in starter players during 265 matches in the three national divisions of Brazilian women's soccer (League A1, League A2, League A3). Additionally, this study investigated the existence of RAE among the four teams with the worst and best performance, as well as among the age ranges of the athletes (cluster analysis: age-group 1 [AG1]1: 15-22 years; age-group 2 [AG2]: 23-28 years; age-group 3 [AG3]: 29-44 years). The athletes were distributed according to their month of birth into four quartiles: Q1 (Jan-Mar), Q2 (Apr-Jun), Q3 (Jul-Sep) and Q4 (Oct-Dec). The RAE was only observed among players in the Women's Brazilian League A2. When considering only the teams with the best performance, a greater distribution of athletes was observed in the third quartile (Q3: Jul-Sep) in all competitions, "reversing" RAE. When considering the distributions among the age ranges, the RAE was only observed among the youngest players (AG1: 15-22 years). The data presented provides significant insights into understanding the development of women's soccer and how the RAE relates to this dynamic. Furthermore, these results point to the complexity of this phenomenon and the need for a multifactorial approach, including investment, team structuring and policies for the development of young athletes, aimed at assisting in the development of women's soccer in Brazil.