Small Relative Age Effect Appears in Professional Female Italian Team Sports

The relative age effect (RAE) concerns those (dis)advantages and outcomes resulting from an interaction between the dates of selection and birthdates. Although this phenomenon is well known in a male context, limited data are available in female sports. Thus, the aim of this study was to quantify the prevalence and magnitude of the RAE in a female Italian context at the professional level in basketball, soccer, and volleyball. A total of 1535 birthdates of elite senior players were analyzed overall and separately between early and late career stages. Chi-square goodness-of-fit tests were applied to investigate the RAE in each sport. An asymmetry in birthdates was observed in all sports (Crammer’s V ranged = 0.10–0.12). Players born close to the beginning of the year were 1.62 and 1.61 times more likely to reach first and second Italian divisions of soccer and volleyball, respectively, than those born in the last part of the year. A small over-representation of female athletes born close to the beginning of the year is evident at the senior professional level in all Italian investigated team sports. In soccer, this trend was more evident in the first stage of a senior career.

The New Generation of Professional Soccer Talent Is Born under the Bias of the RAE: Relative Age Effect in International Male Youth Soccer Championships

In 2019, numerous championships of youth categories soccer national teams were held. In the present study, we analyzed the existence of the Relative Age Effect (RAE) in four major male championships that, due to their importance and participating teams, most likely brought together the great bulk of the players who will dominate professional soccer in the next decade. Participants were professional and amateur youth male soccer players who participated in the last international championships: UEFA European Under-21 Championship (2017–2019); UEFA European Under-19 Championship (2019); South American Youth Football Championship (also known as Conmebol U-20) (2019); and FIFA U-20 World Cup (2019), with 823 players (20.25 ± 0.84 years). In the four championships analyzed, the existence of RAE was found for all players (p < 0.001). Analyzing the players when considering their position on the pitch and their championship, RAE was found, statistically significant, in 10 of the 16 classifications. New generations of elite soccer players arrive with a clear bias in the selection of talent; an unfair bias, based on unequal opportunities in early categories, which should be reviewed by sports authorities.

Relative Age Effect and Talent Identification in Youth Volleyball Players from the Polish Volleyball Federation Sports School

Introduction. This study sought to determine differences in the quarterly age distribution of young Polish volleyball players from the Sports School of the Polish Volleyball Federation (SS PVF), to investigate quarterly differences in anthropometric characteristics and jump test results. Material and Methods. RAE of young players from SS PVF (n = 232) born between 1989 and 2002 was identified in the course of the research. Furthermore, the study included anthropometric characteristics and jump test results (attack jump – AJ). Results. The chi-square test (χ2) revealed the overrepresentation of volleyball players born in quarters 1 and 2, both in the case of graduates (χ2 = 27.32, p < 0.0001) and students who did not finish school (χ2 = 17.95, p < 0.0005). Two-way ANOVA for unbalanced data for the Group factor showed significant differences in the value of estimated marginal means in the case of AJ (F(1,214) = 5.907, p < 0.016) and body mass (BM) (F(1,214) = 5.348, p < 0.022). Conclusions. These results point to the need for better understanding of RAE in order to avoid dropping out or the loss of potential talent, which will contribute to even greater development of volleyball in Poland.

The relative age and birth order effect in Japanese professional football

This study examines how the probability of becoming a professional football player depends on the birth month (relative age effect) and birth order. These two factors are random and cannot be controlled by the athlete. If these factors influence the probability of the occurrence of top athletes, they not only create inequality but also close the disciplines to potentially talented athletes, lowering the level of competition. Therefore, in this study, we statistically clarified the presence or absence of “giftedness of life” by focusing on the birth month and birth order of professional football league players in the Japan Professional Football League (J-League). Our results indicate that the probability of the occurrence of J-League players decreases significantly with increasing birth order and birth month (180 days, from April onward). Moreover, we found that second-born players with an older brother had higher estimated salaries than players without siblings. These results reveal the characteristics of excellent football players and suggest the importance and direction of improvement in talent discovery and development in sports. Based on our results, we recommend improvements in the player training system to buffer the effects of relative age effect and birth order.

Are the Player Selection Process and Performance Influenced by Relative Age Effect in Elite Women’s Handball?

The relative age effect (RAE) is a phenomenon present in team sports, but it does not influence each gender to the same extent. This study aimed to examine the RAE and its relation to performance in international women's handball competitions (2017/18 World Championships). The sample was composed of 1,096 female players distributed into three categories: youth or under 18 (n = 369); junior or under 20 (n = 328) and senior (n = 399). The teams were divided into four groups based on their final position (medalist, quarter-finalist, eight-finalist and bottom-eight teams). The birthdate distribution (trimesters and semesters) was analysed according to the competition category and the playing position. Differences between the expected and observed birthdate distribution were checked using the chi-square statistical test followed by the calculation of the odds ratio. The results revealed, by trimester, the presence of the RAE in the youth (x2(7) = 87.22; p < 0.001) and junior (x2 (7) = 33.12; p < 0.001) categories, with no impact on senior (p > 0.05). The effect size was relatively strong in the youth category (Vc = 0.48). By semester, the prevalence of the RAE was also found in the senior category (p < 0.05). According to the playing position, the RAE was especially detected in ‘goalkeeper’ (p < 0.01) and ‘centre-back’ (p < 0.05) positions, both in U-18 and U-20 categories. Surprisingly, this effect also appeared in the ‘back’ players in the senior category (p < 0.05). A prevalence of the RAE was identified in teams with a higher final position, but interestingly had a greater impact in the quarter-finalist teams (p < 0.001) than in the medalist teams (p < 0.01). The findings demonstrated that the RAE tends to decrease as the chronological age of players increases, demonstrating a strong presence according to collective performance in international women’s handball.

Is there a Relative Age Effect in the Competition Total Scores and its Components of Junior Individual Rhythmic Gymnasts?

Background: Children born at the beginning of the year may be cognitively, emotionally, and physically more advantageous than those born at the end of the year. Aim: This study aims to determine whether there is a relative age effect (RAE) on the total scores and its components of the gymnasts in their routines, competing in the 1st Rhythmic Gymnastics Junior World Championships Individual All-Around Ranking-Apparatus Qualification in 2019. Methods: 138 gymnasts from 61 countries participated in this competition and 61 gymnasts competed in each apparatus. The total scores (TS) and its components in gymnasts' competition routines were analyzed according to gymnasts' age groups (13, 14, and 15 years old) and period of birth [Group I (those born in the first six months of the year), Group II (those born in the last six months of the year)]. Differences and percentages of change between the two periods were examined. A total of 732 scores (Difficulty, Execution, and Total Scores) were evaluated. Descriptive statistics and the One-Way Analysis of Variance (ANOVA) Test analysis were used for statistical evaluation. Results: When the TS and its components were examined in all age groups and all routines, no significant difference was observed between Group I and Group II in terms of RAE. Conclusion: It is thought that considering the RAE in talent selection and orientation programs, participation in sports activities and performance evaluation may be useful for athletes, coaches, and administrators. Keywords: Rhythmic gymnastics, competition performance scores, relative age effect, gymnast