Athletic Performance and Birth Month: Is the Relative Age Effect More than just Selection Bias?

The purpose of this investigation was to evaluate relative age effects (RAEs) in elite youth judo athletes from different chronological age groups, between sexes, and across weight categories. Data from 1542 place winners of the cadet (under 17 y, 2009-2013) and junior judo world championships (under 20/21 y, 1990-2013) were separated by birth month into quarters (Q1, Q2, Q3, and Q4). The observed values were compared with expected annual age distributions using χ2 analyses, and odd ratios (OR) were used to evaluate effect sizes between quarters. The observed frequency of place winners was significantly different from the expected frequency for the age-group and sex comparisons and all body-mass groups (P < .05) with the exception of the extra-light categories (P = .572). When comparing Q1 with Q4 (OR, 95% confidence interval), small effect sizes were observed for cadets (1.72, 1.12-2.66), juniors (1.54, 1.23-1.94), males (1.75, 1.32-2.33), females (1.39, 1.03-1.87), and the light- (1.79, 1.21-2.64) and middle-weight (1.80, 1.20-2.70) categories. RAEs are apparent in cadet and junior judo athletes. Thus, coaches and administrators should consider the potential for physical and/or competitive advantages while adopting strategies that encourage long-term participation in youth judo athletes.

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Relative age effect in U-16 Asian Championship Soccer Tournament

Malaysian Journal of Movement Health & Exercise ◽

10.15282/mohe.v9i1.362 ◽

2020 ◽

Vol 9 (1) ◽

Author(s):

Pathmanathan K. Suppiah ◽

Jeffrey Low Fook Lee ◽

Abdul Muiz Nor Azmi ◽

Hasnol Noordin ◽

Rabiu Muazu Musa

Keyword(s):

Age Effect ◽

Soccer Players ◽

Month Of Birth ◽

Chi Square ◽

Youth Soccer ◽

Relative Age ◽

Relative Age Effect ◽

Birth Month ◽

Older Athletes ◽

Cognitive Knowledge

Athletes born at the beginning of the year may present the advantage of physical characteristics, motor ability or cognitive knowledge that could increase their chances for selection against their peers. This circumstance could lead to the over-representation of older athletes in an age-defined competition which is commonly referred to as relative age effect (RAE). Although, a number of studies have demonstrated that RAE is apparent in youth soccer, such studies barely investigates the performance advantage that may likely exists across the birth month of the athletes. The current study aims to determine the presence of RAE in the under 16 Asian Football Confederation Championship (AFC), investigate the effect of RAE on the team qualification success as well as ascertain the existence of RAE in the playing position amongst the soccer players. Data of the 2018 AFC under 16 qualifications matches were obtained from the AFC. A total of 719 players from 32 countries participated in the qualification competitions. Chi-square for goodness fit is used to determine the existence of the RAE across the players’ month of birth while logistic regression is applied to analyze the differences of the quartiles’ distribution with respect to the quartile, qualification status (qualifier or non-qualifier) as well as the playing position of the players. The results demonstrate the presence of RAE in the AFC under 16 soccer tournaments [χ2(4) = 21.53; p < 0.001] with the largest number of older players dominating the qualified team. Likewise, a substantial difference is observed with regards to the quartile and various playing position of the players p < 0.05.

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The relative age and birth order effect in Japanese professional football

International Journal of Sports Science & Coaching ◽

10.1177/17479541211054239 ◽

2021 ◽

pp. 174795412110542

Author(s):

Dai Yamamoto ◽

Jun Takafuji ◽

Tomoyuki Kato ◽

Kazutake Kawai ◽

Chihiro Shimizu

Keyword(s):

Birth Order ◽

Football Player ◽

Order Effect ◽

Age Effect ◽

Training System ◽

Professional Football ◽

Relative Age ◽

Relative Age Effect ◽

Birth Month ◽

Two Factors

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.

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Early Single Sport Specialization in a High-Achieving US Athlete Population: Comparing National Collegiate Athletic Association Student-Athletes and Undergraduate Students

Journal of Athletic Training ◽

10.4085/1062-6050-431-18 ◽

2019 ◽

Vol 54 (10) ◽

pp. 1050-1054 ◽

Cited By ~ 2

Author(s):

John P. DiFiori ◽

Celeste Quitiquit ◽

Aaron Gray ◽

Edward J. Kimlin ◽

Ryan Baker

Keyword(s):

Student Athletes ◽

Sport Participation ◽

National Collegiate Athletic Association ◽

Age Effect ◽

Division I ◽

Cross Sectional Survey ◽

Relative Age ◽

Relative Age Effect ◽

Birth Month ◽

Potential Marker

Context Early single-sport specialization and the relative age effect are often cited as improving the chances of sport success. Both concepts suggest that genetics and the environment have little influence on sport success. Objective To compare National Collegiate Athletic Association Division I student-athletes (SAs) with their undergraduate nonathlete peers (NAs) in terms of birth month, age of sport initiation, and age of single-sport specialization. A family history of sport participation was examined as a potential marker for genetic and social influences. Design Cross-sectional survey. Setting Large urban university. Patients or Other Participants A total of 273 Division I SAs (138 women, 135 men) and 155 NAs (78 women, 77 men) participated. The NAs had been involved in competitive youth sports before entering the university. Main Outcome Measure(s) Participants were asked to complete a questionnaire that addressed the age of sport initiation, birth month, age of single-sport specialization, and parental and sibling sport achievement. Main Results Neither birth month nor the age of sport initiation differed between groups (age of sport initiation = 7.16 ± 2.6 years for the SAs versus 7.71 ± 3.5 for the NAs; P = .176). A larger proportion of SAs began participating before 10 years of age (80% versus 63%; P = .02). The parents of SAs were more likely to have participated in collegiate (32.4% versus 8.4%; P < .0001) and professional (10.9% versus 1.3%; P = .0005) sports. The SAs specialized in a single sport at an older age (15.38 ± 2.7 years versus 14.30 ± 2.6 years; P = .002). Both groups participated in multiple sports in childhood (SAs = 3.9 ± 1.8 sports, NAs = 3.2 ± 1.8 sports; P = .366). Conclusions The Division I SAs did not specialize in a single sport at a younger age than the NAs. No evidence of a relative age effect was present. Importantly, higher levels of sport achievement among the parents and siblings of SAs suggest that genetic endowment and family or other environmental dynamics play a large role in athletic performance. Overall, the results are not consistent with deliberate practice theory and point toward an alternative model that includes not only sport-specific skill development but also genetic and social factors as key elements of long-term sport achievement.

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The relative age effect in German 11- to 18-year-old male and female swimmers

German Journal of Exercise and Sport Research ◽

10.1007/s12662-020-00677-4 ◽

2020 ◽

Vol 50 (4) ◽

pp. 453-462

Author(s):

Ilka Staub ◽

Robert K. Stallman ◽

Tobias Vogt

Keyword(s):

Age Groups ◽

Age Effect ◽

Effect Sizes ◽

Relative Age ◽

Relative Age Effect ◽

Birth Month ◽

Older Athletes ◽

Time Period ◽

Coaching Training ◽

The Impact

Abstract Relatively older athletes have a greater probability of being selected and subsequently exposed to a higher level of coaching, training and other talent-promoting factors. Grouping by chronological age is, therefore, considered to be one of the weaknesses in talent identification. A large number of studies have confirmed the prevalence of the relative age effect (RAE) across various sports, including swimming. This investigation aims to quantify the prevalence, magnitude and transient pattern of the RAE according to sex and events across German swimmers. The RAE was examined top-100 ranked swimmers (2004–2013) according to birth month, of three cohorts (born 1993–1995; n = 3630) for the age groups 11–18. The Χ2 tests and Cramer’s V estimated effect sizes; odd’s ratios and confidence intervals calculated relative discrepancies between the quartiles. The RAE is significantly present over all events for female swimmers until 13–15 and for males until 16–18 years of age. Effect sizes were moderate until 12/13 years of age for females and 14/15 years of age for males. No inverted effects were visible. Compared to previous reports on Australian as well as Portuguese cohorts, the RAE was prevalent over a longer time period. Therefore, the impact of negative outcomes from RAE appears to be greater among German age group swimmers.

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