Purpose. this study investigated the occurrence of relative age effect (RAE) in Brazilian elite soccer athletes depending on age categories, playing position, and competitive level. Methods. Data from 2660 male elite soccer athletes who participated in the 2019 Brazilian soccer championships were analysed. to determine RAE, the players were divided by their quarter of birth: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December). Data were obtained from the Brazilian Soccer Confederation (CBF) official website, and from each club's website when no information was available at the CBF website. Were included the athletes who participated in the 2019 Brazilian soccer championships in series A and B. Data were organized in accordance with age categories (under-20 or senior), playing position (forwards, midfielders, defenders, and goalkeepers), and competitive level (Series A or B).Results. An overrepresentation of soccer players born in the first quarter of the year was found when compared with the other quarters, whereas players born in the last quarter of the year were underrepresented, regardless of the age category and competitive level. Regarding playing position, an overrepresentation of soccer players born in the first quarter of the year was found for all playing positions in both age categories, except for the goalkeepers in the senior category. Conclusions. Our results showed a prevalence of RAE in U-20 and senior age categories in elite Brazilian soccer athletes, in both competitive levels, and for all playing positions, except for goalkeepers in the senior category.

The present study aimed to investigate the prevalence of RAE in soccer players from different positions in Series A and B in 2020 Brazilian soccer, as well as the impact of RAE on the estimated market value of these players. Methods: Data from 1080 male elite soccer athletes were analyzed. Athletes were grouped according to birth quarters: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December) and the competitive level (Series A or B). Chi-square tests (χ 2 ) were performed to compare the birthdates' distribution of athletes according to a competitive level and playing positions. Kruskal-Wallis test was used to compare the market values of players born in each of the quarters of the year across competitive levels and playing positions. The significance level was set at 5%. Results:The overall analyses showed the prevalence of RAE in Series A and B, with an overrepresentation of athletes born in the first two quarters of the year. The RAE analysis based on playing positions showed different from expected distributions for forwards, midfielders, and defenders in Series A. In Series B, only midfielders showed a difference from the expected distribution. As for the market values analyses, no differences were found based on the athletes' birth quarters, regardless of competitive level or playing position. Conclusion: Our results indicate that, although RAE is prevalent in Series A and B of elite Brazilian soccer, it does not seem to influence players' estimated market values.