This study aimed to investigate the impact of crowd absence due to the COVID-19 pandemic on home advantage in Series A and B of professional Brazilian male soccer. Moreover, we sought to compare the home advantage between different competitive levels. Data from 2018 to 2020 Brazilian professional soccer championships (Series A and B) were analyzed, consisting of 2280 matches. The effect of home advantage was calculated in relation to the number of points won, the number of wins, goals scored and goals conceded. Our results indicated that home advantage was reduced in Serie A. Specifically, the 2020 (absence of the crowd) and 2019 seasons showed smaller home advantage compared to the 2018 season. On the other hand, Serie B analyses indicated no changes in home advantage over the seasons analyzed. The comparison of home advantage between competitive levels indicated higher home advantage in Serie A, exclusively in the 2018 season. In addition to the absence of fans, other changes occurred in elite sports due to the pandemic, such as changes in rules and the calendar. Considering that home advantage is affected by multiple interacting factors, it is important to investigate specific sports leagues across the world to determine which factors had the greatest impact on the advantage of playing home matches.

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.

This study investigated the Relative Age Effect (RAE) in school athletes, according to sex and age categories. Birthdates from 1356 male and 1044 female athletes (aged 9 to 17 years) who played scholar competitions in Minas Gerais-Brazil in 2018 and/or 2019 in categories Under-11, Under-14 and/or Under-17 were analyzed. Athletes were divided into quarters according to their month of birth: Q1 (January-March), Q2 (April-June), Q3 (July-September), and Q4 (October-December). Chi-squared tests were performed to verify the presence of RAE. The significance level was set at 5%. The observed distribution was different from expected when all athletes were analyzed together (p = 0.019; ⍵ = 0.06), and in males when athletes were analyzed separately by sex (p = 0.017; ⍵ = 0.09). Athletes born in the three first months of the year were more frequent in both cases (p < 0.008). The age category analyses indicated uneven distribution of births in Under-11 category (p < 0.001; ⍵ = 0.25), where athletes born in Q1 and Q2 were more frequent (p < 0.001). When age category and sex were considered together, it was observed that athletes born in Q1 were more frequent than athletes born in Q3 (p < 0.002) and Q4 (p < 0.001) in the U-11 category regardless of sex (p < 0.002), but not in the Under-14 and Under-17 categories. Considering that school sport can be the first step towards achieving higher competitive levels, it is important to instruct coaches about RAE, in order to reduce inequalities in the access to school sport. Este estudio investigaba el Efecto de la Edad Relativa (EEA) en atletas escolares, según categorías y género. Han sido analizados 1356 jugadores masculinos y 1044 femeninas (de 9 a 17 años) que participaron en competencias escolares en Minas Gerais-Brasil en 2018 y/o 2019 en las categorías Sub-11, Sub-14 y/o Sub-17. Los jugadores fueron divididos en cuartos, de acuerdo con el mes de nacimiento: Q1 (enero-marzo), Q2 (abril-junio), Q3 (julio-septiembre) y Q4 (octubre-diciembre). Se realizaron pruebas de chi-cuadrado para verificar la presencia de EEA. El nivel de significación fue 5%. La distribución observada difirió de la esperada cuando todos los jugadores fueron analizados juntos (p = 0.019; ⍵ = 0.06), y en los hombres, cuando los jugadores fueron analizados por género (p = 0.017; ⍵ = 0.09). En ambos casos se encontró una mayor proporción de jugadores nacidos en los primeros meses del año (p < 0.008). Los resultados indicaron una distribución desigual de nacimientos en la categoría Sub-11 (p < 0.001; ⍵ = 0.25), en la que deportistas nacidos en Q1 y Q2 fueron más frecuentes (p < 0.001). Cuando se analizaron juntos categoría y género, se observó que atletas nacidos en Q1 fueron más frecuentes que los deportistas nacidos en Q3 (p < 0.002) y Q4 (p < 0.001) en la Sub-11, independientemente del género (p < 0.002), pero no en las categorías Sub-14 y Sub-17. Teniendo en cuenta que el deporte escolar puede ser el primer paso para alcanzar mayores niveles competitivos, es importante instruir a los entrenadores sobre el EEA, con el fin de reducir las desigualdades en el acceso al deporte escolar. Este estudo investigou o Efeito da Idade Relativa (EIR) em atletas escolares, de acordo com categorias e sexo. Analisaram-se datas de nascimento de 1356 atletas do sexo masculino e 1044 do sexo feminino (de 9 a 17 anos) que participaram de competições escolares em Minas Gerais-Brasil em 2018 e/ou 2019 nas categorias Sub-11, Sub-14 e/ou Sub-17. Os atletas foram divididos em quartis, de acordo com o mês de nascimento: Q1 (janeiro-março), Q2 (abril-junho), Q3 (julho-setembro) e Q4 (outubro-dezembro). Realizaram-se testes de chi-quadrado para verificar a presença do EIR. O nível de significância adotado foi de 5%. A distribuição observada diferiu do esperado quando todos os atletas foram analisados em conjunto (p = 0.019; ⍵ = 0.06), e no sexo masculino, quando os atletas foram analisados por sexo (p = 0.017; ⍵ = 0.09). Encontrou-se maior proporção de atletas nascidos nos primeiros meses do ano em ambos os casos (p < 0.008). Os resultados indicaram uma distribuição desigual de nascimentos na categoria Sub-11 (p < 0.001; ⍵ = 0.25), onde atletas nascidos nos Q1 e Q2 foram mais frequentes (p < 0.001). Quando a categoria e o sexo foram analisados conjuntamente, se observou que atletas nascidos no Q1 foram mais frequentes que atletas nascidos em Q3 (p < 0.002) e Q4 (p < 0.001) no Sub-11, independentemente do sexo (p < 0.002), mas não nas categorias Sub-14 e Sub-17. Considerando que o esporte escolar pode ser o primeiro passo para alcançar maiores níveis competitivos, é importante instruir os treinadores sobre o EIR, a fim de reduzir as desigualdades de oportunidades de acesso ao esporte escolar.

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