Prevalence Of Relative Age Effect Research Articles

Selection and re-selection throughout a national talent pathway: Exploring longitudinal relative age effects in Northern Ireland male soccer

ABSTRACT The purpose of this study was to investigate the longitudinal prevalence of relative age effects (RAEs) across playing levels and positions in Northern Ireland international male soccer. Birthdates of U17 (n = 276), U19 (n = 320), U21 (n = 331), and senior (n = 108) international players between 2011 and 2023 were recorded. Chi-square tests and odds ratios with 95% confidence intervals were used to compare observed and expected birthdate distributions. A selection bias toward relatively older players was evident at U17 and U19 playing levels as well as defensive and midfield positions. In contrast, more relatively younger senior and forward players were selected. Longitudinal analyses revealed that of those players who were initially selected at U17, more relatively older players were re-selected at subsequent playing levels, but there were no birthdate asymmetries amongst new players added after U17. The results of this study demonstrate RAEs are prevalent across Northern Ireland international male soccer and are influenced by playing level as well as position. These findings have important implications for policy makers and practitioners as relatively older players are overrepresented at youth but not senior level, which questions the efficacy of this (un)conscious bias in the talent pathway.

Biological maturity and relative age effects in German age-group swimming

Relative age effects (RAE) refer to a skewed distribution with an overrepresentation of athletes born close to the selection date. The prevalence of RAE has been repeatedly demonstrated in youth swimming. Additionally, being more mature within an age group is associated with consistent selection advantages. The present study aims to determine (1) the prevalence and magnitude of RAE in youth swimming and (2) the relation to anthropometry and biological maturity status. The study included 650 swimmers (male n = 273, age 11.00 ± 1.27 years; female n = 377, age 11.00 ± 1.25 years). The dates of birth were split into four birth quartiles (Q). The maturity status was assessed using equations to estimate the age of peak height velocity (APHV). χ2 tests and analysis of variance (ANOVA) were used for statistical analyses. The χ2 tests have shown significant RAE with medium effect sizes (ES; p < 0.001, 0.18 < V < 0.20) for male and female athletes. Also, the results have shown significant RAE with medium effect sizes (ES; p < 0.001, 0.18 < V < 0.20). ANOVA has not revealed significant differences regarding body height, body mass, and APHV between the four birth quartiles for both sexes, except for body mass in female athletes (p = 0.037). The findings indicate that maturity status and anthropometry influence RAE in youth swimming. It can be assumed that relatively younger swimmers can counteract their disadvantage only by similar anthropometric and maturity-related characteristics to the relatively older swimmers, which significantly impacts talent identification and development of swimmers.

Relative age effect across the talent identification process of youth female soccer players in the United States: Influence of birth year, position, biological maturation, and skill level.

The aims of the study were to examine the relative age effect (RAE) in youth female soccer players in the United States (US) and the influence of birth year, playing position, estimated maturation and skill ratings. The sample consisted of 3,364 youth female soccer players who were active in the 2021-2022 US soccer season across three main stages of the talent identification (TID) process for Youth National Team (YNT) players (i.e., Club, TID Center, and YNT). A prevalent RAE for players born in Q1 was present in the full sample. A significant prevalence for Q1 players were identified for both Club and TID Center, but not YNT. A significant RAE prevalence for Q1 players was identified for most of the age groups from U13-U18 at Club (except U18) and TID Center (except U17). Significant RAEs prevalence for players born in Q1 were found in Goalkeepers, Center Backs, Midfielders, and Center Forwards at Club and TID Center (except Wide Forwards). The data identified a consistent RAE prevalence for Q1 players in early and on-time-maturers across all levels. An even birthdate spread was evident in YNT with a prevalence for Q4 players and a higher percentage of late-maturers than elsewhere in the TID process. Results reinforce evidence indicating RAEs still exist in soccer, yet show for the first time within a youth female soccer TID process, the influence of contextual factors on the prevalence of RAE. This information can be used to advance TID and development across the US soccer landscape.

The Relative Age Effect in Ice Hockey: Analysis of Its Presence, Its Fading and of a Reversal Effect among Junior and Professional Leagues.

This study analyzes the relative age effect (RAE) among the world's best junior hockey leagues and in the NHL. Despite the prevalence of RAE in ice hockey, past research suggests its fading-reversal over time, which may occur at later stages of athletic development. The hypothesis of the RAE reversal was tested with two sources of raw data files from the 2021-2022 season: 15 of the best international junior and minor professional leagues (N = 7 399) and the NHL (N = 812). Birth quartile distributions were analyzed to verify the prevalence of RAE and quantile regression was used to test the reversal of RAE hypotheses. Advanced hockey metrics were aggregated from multiple data sources and used to compare early born with late born players using birth quartiles. Prevalence of the RAE was verified with crosstabs analyses and quantile regression was used to test the reversal effect. Results indicated that the RAE still prevailed in ice hockey, with higher magnitude in Canadian leagues. Regression analyses showed that late-born junior and minor pro players, despite getting less exposure in terms of games played, attained levels of offensive production similar to those of early born players. Late-born players able to emerge in the NHL performed similarly and sometimes displayed better performance (in some markers). Results suggest that stakeholders should find ways to pay special attention to late born players in talent identification processes and offer them opportunities to develop at the highest levels.

The prevalence of relative age effects and the influence of the talent pool size on Australian male and female youth football

ABSTRACT The current study explored the association between talent pool size and relative age effects in Football Australia’s talent pathway. It also compared relative age effects between male and female players. Participants were 54,207 youth football players (females: n = 12,527, age-range = 14.0–15.9; males: n = 41,680, age-range = 13.0–14.9) eligible for the National Youth Championships. We developed linear regression models to examine the association between the member federation size and the probability of a player being born earlier in the year. We also analysed selection probabilities based on birth quartile and year half across three layers. Overall, talent pool size was associated with a higher probability of selecting a player born in the first half of the year over the second. More specifically, an increase of 760 players led to a 1% higher selection probability for those born in the first six months of a chronological age group. In addition, there were more occurrences of relative age effects in the male than the female sample. Future studies should focus on the impact of the talent pool size on relative age effects at each major talent identification/selection stage of a talent pathway.

Low prevalence of relative age effects in Luxembourg's male and female youth football.

The relative age effect (RAE) is a well-established phenomenon in football. However, while the majority of previous studies focussed on established football nations, it remains unclear if the constraint of a limited population of soccer players in smaller countries associated with less strict selection procedures may reduce the risk of RAE. This study aims to investigate the RAE in Luxembourg that follows an 'open-door' selection policy in youth football due to the limited pool of players. Birthdates from all licensed and actively playing Luxembourgish youth footballers including all players of the youth national teams (396 girls and 10981 boys) competing in the season 2018/2019 were analysed and categorised into birth quarters and semesters. To further investigate a performance dependence of the RAE in amateur leagues, success was determined based on the teams' rankings at the end of the season. Differences between observed and expected birthdate distributions were calculated across all licensed players and age groups, within the national teams, and for the top- and bottom-tier football teams using chi-square statistics. While a RAE was absent across all age groups (except U7), significant RAEs with high effect sizes were observed in the top-level and national teams. These findings contrast the substantial RAE effects in large football nations and suggest that open selection systems might reflect an environmental constraint that limit the prevalence of RAE in football. Further, this study indicates that a performance dependence of the RAE is not limited to high level football but already occurs on an amateur level.

Relative Age Effect on Brazilian male elite futsal athletes according to playing position and performance by goals scored on Brazil National Futsal Leagues

Introduction: The relative age effect is prevalent in different elite team sports. However, little is known about this phenomenon in high-level adult male futsal players. Aim: The present study aimed to investigate the prevalence of relative age effect in Brazilian male elite futsal players, and its relationship with playing position and goals scored on Brazil National Futsal Leagues (BNFL) from 2016 to 2020. Methods: The distribution of birth dates, playing positions, and goals scored by male participants of the Brazil National Futsal Leagues were analyzed. Chi-squared tests were used to analyze the birth dates distribution based on quarters and semesters of the year, according to playing position (defender, winger, pivot, and goalkeeper) and scoring performance (high and low). Results: The overall analysis indicated that the relative age effect is prevalent on the pool of athletes analyzed. However, this effect was position-dependent, since relatively older athletes were overrepresented only in wingers and defenders playing positions. On the other hand, scoring performance was not associated with the relative age effect, since this effect was found in both performance levels. Conclusion: Relative age effects are prevalent in Brazilian male elite futsal athletes, especially for defenders and wingers. Considering the high level of competitiveness for spots in elite futsal teams, coaches and sports administrators must be educated about the prevalence of the relative age effect in this sporting context. This is necessary in order to reduce the inequalities generated by age categories based on arbitrary cut-off dates, which may reduce potential talent loss.

Exploring Relative Age Effects in Youth Ice Hockey Through a Single Team Case Study and Composite Narratives.

Relative age effects (when birthdate influences participation or performance) in sport potentially influence the experiences of sport participants, including athletes, parents, and coaches. Nearly all existing literature on relative age effects adopts a quantitative approach, limiting our understanding of the phenomenon. Thus, the purpose of this unique study was to explore relative age effects using an instrumental, descriptive case study approach with one elite, youth, male ice hockey team. This context was chosen given the high prevalence of relative age effects among such groups. Participants included 20 athletes, 19 parents, and two coaches from one team. Data were collected through biometric measures, semistructured interviews, and participant observations. Results were presented as five composite narratives: relatively older athletes, relatively younger athletes, parents of relatively older athletes, parents of relatively younger athletes, and coaching staff. The narratives demonstrated unique relative age experiences for each group of participants. Discussion aligns the results with the social agents model that explains relative age effects. Practical recommendations for sport participants are also provided.

Relative Age Effect on Youth Female Volleyball Players: A Pilot Study on Its Prevalence and Relationship With Anthropometric and Physiological Characteristics.

The relative age effect (RAE) on human performance has been well studied in many sports, especially in soccer; however, little information has been available about the prevalence of RAE in volleyball, and its role on anthropometric and physiological characteristics. The aim of the present study was to examine (a) the prevalence of RAE in selected (i.e., to be considered for the national team) and non-selected youth female volleyball players, and (b) the relationship of birth quarter (BQ) with anthropometric and physiological characteristics. Selected (n = 72, age 13.3 ± 0.7 years, weight 62.0 ± 7.2 kg, height 1.72 ± 0.06 m) and non-selected female volleyball players (n = 53, age 13.9 ± 1.1 years, weight 56.4 ± 7.3 kg, height 1.66 ± 0.06 m) performed a series of anthropometric and physiological tests. Twenty-six selected participants were born in the first quarter of the year, 19 in the second, 14 in the third, and 13 in the forth. The corresponding frequency by BQ in non-selected participants was 12, 12, 17, and 12. No association was observed between the number of participants and their frequency by BQ neither in the selected (χ2 = 2.79, p = 0.425) nor in the non-selected group (χ2 = 0.64, p = 0.886). Anthropometric and physiological characteristics did not vary by BQ (p > 0.05). The absence of RAE in female volleyball players and the similarities of anthropometric and physiological characteristics among BQ might be due to technical-tactical character of this sport. These findings would be of great practical value for coaches and fitness trainers working with young volleyball players.

Relative Age Effect in Collegiate Soccer: Influence of Nationality, Playing Position, and Class.

Hurley, E, Comstock, BA, Haile, L, and Beyer, KS. Relative age effect in collegiate soccer: influence of nationality, playing position, and class. J Strength Cond Res 33(12): 3295-3301, 2019-The purpose of this study was to evaluate the existence of relative age effects (RAEs) in collegiate soccer. In addition, the impact of nationality, position, class, and National Collegiate Athletic Association (NCAA) tournament qualification status on the prevalence of RAEs was assessed. Birth dates from male NCAA Division I soccer athletes (n = 4,082) from the 2017/2018 season were categorized into quarters based on calendar and scholastic quarters. All athlete birth-date distributions were compared with the expected birth-date distributions for the United States. International-born athletes (INT) displayed a significant difference in birth-date distribution when assessed with calendar quarters, whereas American-born athletes (USA) showed a significant difference in birth-date distributions when assessed with scholastic quarters. Furthermore, INT showed significant RAEs for midfielders and defenders, whereas USA showed significant RAEs midfielders and goalkeepers. In terms of class, INT had significant RAEs for all classes, whereas USA had significant RAEs only for freshmen and sophomores. All INT had significant RAEs regardless of tournament qualification status; however, USA had significant RAEs only for nontournament teams. In summary, significant RAEs exist in male Division I college soccer; however, the presence of RAEs is influenced by nationality, position, class, and NCAA tournament qualification status. Coaches should be aware of RAEs during the recruitment process to avoid potential selection bias.

Prevalence of Relative Age Effect in Russian Soccer: The Role of Chronological Age and Performance.

The relative age effect (RAE) has been well studied in adolescent and adult soccer players; however, less information has been available about children engaged in regular soccer training and the role of performance. Thus, the aim of the present study was to examine the prevalence of RAE in children and adolescent soccer players, as well as the role of age and performance. Russian soccer players (n = 10,446) of various ages, playing positions and performance levels were examined for their date of birth. It was observed that RAE was widespread in Russian soccer teams of all age groups. RAE was most pronounced in children teams of the top tier Russian soccer academies and junior Russia national teams, where the proportions of soccer players born in the first quarter were 43.9% and 39.8%, respectively, whereas those born in the fourth quarter of the year were 7.7% and 6.3%, respectively. In top tier soccer academies, RAE did not vary by age group. In the middle tier soccer academies, RAE was less pronounced. It was still prevalent in the junior teams of the top tier clubs of the Russian Premier League, where 14.3% of the soccer players were born in the fourth quarter of the year compared to 42.9% born in the first quarter of the year. RAE can be observed in the top tier Russian adult teams as well, although it is less pronounced there. In summary, RAE is highly prevalent in Russian children and junior soccer and is associated with the level of competitiveness. At the same time, the proportion of players born in the fourth quarter of the year is higher in adult teams than in junior and youth teams, which is most likely due to the wider selection of players, not limited by their age and place of residence. In junior teams, RAE results in a bias towards selection of players who are more physically mature, whereas children who may be more talented but are less developed due to their younger chronological age tend to be overlooked.

Relative age effect in Turkish soccer

Relative Age Effect (RAE) refers to the difference between the individuals who were born in the early or the later period of the same year. The purpose of this study was to investigate the existence and prevalence of RAE in Turkish Soccer. The data were collected from 3074 (530 professional players and 2544 amateur players) active players who play for eight different age categories of 19 soccer clubs in Turkish First Soccer League. The significance of the distributions by birth month, distributions by quarter-year and the differences between groups were analyzed through chi-square test. For all categories, first month (January%=22.10), and first quarter (Q1%=44.44) of distributions by birth month and were found to be significantly high (p<0.01). The researchers observed the existence and prevalence of RAE in youth and professional teams of Turkish Soccer Clubs. Trainers should evaluate players carefully during talent selection, in order to eliminate this unfair competition.

Relative Age Effects in Welsh Age Grade Rugby Union

Relative age effect (RAE) refers to the immediate and long-term consequences of age difference within an age grouping. In sporting contexts, it has been widely shown that those born in the first quarter gain an advantage over those born in the last quarter of the year. Rugby Union has received scant attention in relation to RAE. The primary purpose of the present study was to examine the presence and prevalence of RAE in Welsh age grade Rugby Union. A further purpose was to consider how coaches' selection processes have the potential to contribute to the manifestation of RAE. A sequential multi-method research typology was adopted to gain a richer, more contextualized understanding of RAE. Results revealed that RAE was evident in all age groups of Welsh junior club rugby from ‘Under 7–19 yrs'. Odds ratios showed that the magnitude of the RAE increases with the three levels of performance (district, regional and national) above the club game. Further, the process of selection had characteristics that increased the risk of RAE occurring, especially a propensity to use physical characteristics as the primary selection criteria when selecting for representative teams. Also, coaches' overemphasis on game performance and winning appeared to determine that the older, potentially bigger, faster, stronger players are preferred over the younger less physically mature players.

Efeito da idade relativa e sua relação com as características morfológicas e de desempenho em jovens futebolistas.

In soccer, the relative age effect (RAE) was observed in both adult and young players. The RAE appears to be more pronounced in elite sports, probably by the need to select the best players to compete internationally. This study review: (1) the prevalence of RAE in soccer players, (a) considering competitive level (b) and specific position and (2) association between RAE (a) and anthropometric characteristics, (b) physical fitness components and technical skills. A total of 12 studies met all inclusion criteria for this review. One trial (meta-analysis) was included after the eligibility process. Overall, 77675 young soccer players were analysed. In all studies, significance level of 0.05 was set for the type I error. There is a consensus about the presence of an RAE in men's soccer, and the percentage of players born in the first quarter in the selection year for professionals is high, with peak values found for elite young athletes, and a large decrease is evident throughout the regional and school representation. The relationship between RAE and the specific position is controversial, according to few studies. It is likely that players born in the first quarter differ in a variety of anthropometric characteristics and physical fitness components compared with peers born in the last quarter. Researchers need to understand the mechanisms by which RAE increase and decrease in order, to reduce and eliminate this social inequality that influence the experiences of athletes, especially in periods of development. Organizational and practical intervention is required.

Survival and Success of the Relatively Oldest in Swiss Youth Skiing Competition

Relative age refers to age differences between children in the same selection year. The present study investigated the prevalence of relative age effects (RAEs) at the Grand Prix Migros (GPM), which is the most popular alpine skiing race for children aged 7 to 14 years in Europe. In total, 17,992 Swiss junior alpine skiers, separated into female skiers ( n = 7,227) and male skiers ( n = 10,765), were evaluated in the 2010, 2011, and 2012 races. Chi-square analyses revealed no RAEs ( p &gt; 0.05) for the entire group of finishers in the qualification race for females in the Under U-8 to U-13 categories ( n = 7,010) and all males ( n = 10,410). Significant inverse RAEs were detected in the qualification race among female skiers in the U-14 and U-15 age categories ( p &lt; 0.01; odds ratio OR = 0.79; 95% confidence interval (CI) [0.64–0.98], and among disqualified male skiers ( p &lt; 0.01; OR = 0.54; [CI, 0.40–0.74]. However, significant RAEs were found for the entire group of both female and male skiers who qualified for the final race ( p &lt; 0.01; OR = 1.49; [CI, 1.28–1.73] of females, respectively OR = 2.18; [CI, 1.87–2.53] of males). RAEs were additionally apparent in all age categories of female and male finalists. The GPM is apparently influenced by RAEs, which may be an initial step towards RAEs in youth sports and may lead to an unequal participation in Swiss skiing.