The Relative Age Effect in the Top 100 ATP Tennis Players 2016–2018

Author(s):  
Michal Bozděch ◽  
Adrián Agricola ◽  
Jiří Nykodým ◽  
Antonín Zderčík ◽  
Tomáš Vodička

The issue of the Relative Age Effect (RAE) has been monitored in the field of sports for more than 30 years. Its theoretical framework is based on the premise that during the pubescent period athletes born at the beginning of the year experience earlier biological acceleration re-sulting in a higher level of physiological, mental, morphological and psychological attributes than their later-born peers. A number of publications show that this temporary advantage often manifests itself in elite competitions at the junior level, but gradually disappears during the transition to professional senior competitions. The aim of this work was to determine the level of the RAE in the elite 100 ATP tennis players (ATP Rankings) in 2016–2018. To assess the influence of the RAE, the Chi-Squared (ꭕ2) test in the variant of Goodness of Fit was used for the assessment of the conformity of expected and observed frequency distribution due to the categorical character of the research data and the large sample size. The Cohen’s w val-ue calculation was used to assess the effect size (ES, since it is not a random representative selection of elements of the research set) of the ꭕ2 test values. The odds ratio (OR) was used to assess the chance of players from the Q individual quarters to get among the best 100 players. The results show that, in terms of effect size (ES), the effect of birth date in all the Top 100 players is small (w = .22) during the entire observed period 2016–2018; the influence of RAE is therefore dismissed. The ES in the individual years is again small (w = .21–.25); the influence of RAE is also dismissed. In analysing the effect of birth date, the mean rate of effect size was found in tennis players in positions 1 to 25 (w = .46) as well as in tennis play-ers in positions 51 to 75 (w = .37); the RAE influence is therefore not rejected. Only a small measure of effect size was found between positions 26 to 50 and 76 to 100 (w = .21–.25); the RAE influence is rejected. No statistically significant difference has been found between the observed and expected distribution of birth date between the observed quarters of the year (odds ratio test, p > .05) and it has not, therefore, been proven that tennis players from any of the quarters Q –Q had a better chance of getting among the Top 100 tennis players. It can be concluded that professional senior tennis had not shown the RAE influence to the extent usual in junior categories during the observed period of 2016–2018.

Author(s):  
Adrián Agricola ◽  
Michal Bozděch ◽  
Martin Zvonař ◽  
Jiří Zháněl

The theory of Relative Age Effect (RAE) works on the assumption that athletes born at the beginning of a calendar year are more successful than athletes born in the end of the year. The athletes born early have a significant probability of a higher level of physiological, mor-phological and psychological abilities than later born athletes. Several studies show that the RAE was not found in females or it was significantly lower than in males. The research objective was to find out the influence of RAE in WTA Tour TOP100 female professional tennis players (n=500) in 2014–2018. Cohen’s effect size (ES) w was calculated to assess the level of the influence of RAE. To assess the differences between the observed and the expected relative age quarter distribution, Chi-Square test (ꭕ2) was used. In terms of effect size (ES), a medium influence of RAE has been proven in 2016 and 2017 (w = 0.33, resp. w = 0.30); a small influence has been proven in years 2014, 2015, 2018 and in the whole observed period 2014–2018. Based on statistical analysis, the influence of RAE cannot be rejected in years 2016 (p 0.05). The next step was to assess the influence of RAE on the final WTA ranking in 2014–2018. Players have been divided into four intervals: 1–25, 26–50, 51–75 and 76–100 positions. ES has showed the medium influence of RAE in 76–100 positions (w = 0.34); only small influence of RAE was found in other positions. Statistical analysis showed that the influence of RAE cannot be rejected in 1–25, 26–50 and 76–100 positions (p < 0.05): it can be rejected in 54–75 positions. The results of the research have shown the medium influence of RAE in 2016 and 2017: in the recent years (and in the whole observed period of 2014–2018), the influence of RAE was small. The influence of RAE on the final WTA ranking is also small, except the 76–100 positions.


2016 ◽  
Vol 11 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Sabrina Skorski ◽  
Stefan Skorski ◽  
Oliver Faude ◽  
Daniel Hammes ◽  
Tim Meyer

Purpose:To investigate whether anthropometric profiles and fitness measures vary according to birth-date distribution in the German national youth soccer teams and to analyze whether there is a difference in the chance of becoming a professional soccer player depending on birth quarter (BQ).Methods:First, 554 players were divided into 6 age groups (U16–U21), each subdivided into 4 BQs. Every player performed at least one 30-m sprint, a countermovement jump, and an incremental test to determine individual anaerobic threshold. For players performing more than 1 test within a team, the best 1 was included. Since some players were part of several different teams, a total of 832 data sets from 495 individual soccer players, all born from 1987 to 1995, divided into 6 age categories (U16–U21) were included.Results:Overall, more players were born in BQ1 than in all other BQs (P < .05). No significant difference between BQs could be observed in any anthropometric or performance characteristics (P > .18). Players born in BQ4 were more likely to become professional than those born in BQ1 (odds ratio 3.04, confidence limits 1.53–6.06).Conclusion:A relative age effect exists in elite German youth soccer, but it is not explained by an advantage in anthropometric or performance-related parameters. Younger players selected into national teams have a greater chance to become professionals later in their career.


2021 ◽  
Vol 11 ◽  
Author(s):  
Martin Götze ◽  
Matthias W. Hoppe

The relative age effect (RAE) is associated with (dis)advantages in competitive sports. While the RAE in elite male soccer reveals a skewed birthdate distribution in relation to a certain cut-off date, research of RAE in elite female soccer is affected by small number of samples and conflicting results. The purpose of this study was to investigate the RAE in elite adult German soccer regarding gender and competition level. The sample comprised 680 female and 1,083 male players of the two top German leagues during the 2019/20 season and German national teams (A-Team to Under 19). Differences between the observed and expected birthdate distributions were analyzed using chi-square statistics and effect sizes followed by calculating odds ratios. Results showed a statistically significant RAE with small effect size across all players included for both genders (female players: P &lt; 0.001, W = 0.16, male players: P &lt; 0.001, W = 0.23). The identified RAE was based on an over-representation of players born at the beginning of the year. According to gender and competition level, RAEs were more pronounced in German male soccer. While significant RAEs were found among males in the first two leagues (first league: P &lt; 0.001, W = 0.19, second league: P &lt; 0.001, W = 0.26), the RAE of females was more pronounced in the second league (first league: P = 0.080, W = 0.16, second league: P = 0.002, W = 0.20). The analysis of RAE regarding the national teams revealed a statistically significant RAE with large effect size for only the youngest investigated age group of male players (Under 19: P = 0.022, W = 0.52). Our data show an RAE in female and male German adult soccer, which could be accompanied by a loss of valuable elite players during the youth phase of the career. Consequently, the pool of talented players at the adult level would be limited.


2013 ◽  
Vol 3 (1) ◽  
pp. 74-79 ◽  
Author(s):  
William E Garrett ◽  
Patrick W Joyner ◽  
William J Mallon ◽  
Donald T Kirkendall

ABSTRACT The relative age effect (RAE) refers to the oversampling of youth born in the first quarter of the birth year when auditioning for selected age-restricted sports. This advantage conferred to the older athlete is the result of the older athlete being more physically and emotionally mature and, therefore, assumed to be a more advanced player. Chosen players will be exposed to better coaching, competition, teammates, and facilities in their respective sport. This RAE was first described in 1988 for ice hockey, and has since been described in numerous other sports, with a vast majority of the literature demonstrating an RAE in small cohorts, as well as in team sports and sports that incorporate a ball (i.e. soccer, basketball, hockey, etc). We extended the exploration of an RAE beyond specific sports by examining the birth quarter of over 44,000 Olympic athletes birth dates, born between 1964 and 1996. Our hypothesis is that not only did an RAE exist in Olympic athletes, but that it existed across selected categories of athletes (by gender), such as team vs individual sports, winter vs summer athletes, and sports using a ball vs those not using a ball. The fractions of births in the first vs the fourth quarter of the year were significantly different (p < 0.001) from each other for the summer and winter Olympians, ball and nonball sports, and team as well as individual sports. This significant difference was not gender specific. We found the general existence of an RAE in Olympic athletes regardless of global classification. Joyner PW, Mallon WJ, Kirkendall DT, Garrett WE Jr. Relative Age Effect: Beyond the Youth Phenomenon. The Duke Orthop J 2013;3(1):74-79.


2021 ◽  
pp. 86-89
Author(s):  
Matej Babić ◽  
Dražen Čular ◽  
Igor Jelaska

Aim of this research was to identify and analyse relative age effect (RAE) on sample composed of young Croatian taekwondo competitors. In order with aim of research, for medal winners (n1=72) and other competitors (n2=187) who competed at Croatian taekwondo cadet championship 2015, date of birth, weight category and sport success were extracted. By conducting of Chi-square test on all competitors (n=259) it is proven there is non-significant difference (χ2=12.28; p=0.34) between expected and observed frequencies according to month of birth. Furthermore, significant difference between observed and expected frequencies according to year of birth of medal winners (χ2=45.31; p<0.01) is confirmed. Results of this research are pointing on presence of RAE which could lead to mistakes in selection of young athletes. Authors are suggesting to minimize allowed age range for competition, or to separate competitors in more age categories, which would enable more equal competitions and reduce effect of age on sport success.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254687
Author(s):  
Susana M. Gil ◽  
Iraia Bidaurrazaga-Letona ◽  
Jon Larruskain ◽  
Izaro Esain ◽  
Jon Irazusta

The relative age effect (RAE) has primarily been investigated in male athletes involved in popular sports and high-level competitions. However, occurrence of RAE in other types of sports at the grassroots level, particularly in female athletes, is less well-studied. Thus, we examined the RAE in a large cohort of young athletes who participated in all competitive sports in Bizkaia, Spain, according to gender and specificity of the sport. The birth dates of 38,381 participants (65.1% males and 34.9% females) aged 9–14 years old in 37 competitive sports were analyzed. Birth dates were divided into four birth-quarters and compared to those of all children born in the same period using a χ2 goodness-of-fit test and standardized residuals. The effect size Cramer’s V was measured, and odds ratio and 95% confidence intervals were calculated to determine the odds of athletes born in January playing in the highest leagues. In the total sample, in boys RAE was evident in football, but only in higher-competition leagues (p<0.001, large effect size). In girls, RAE was evident in the most popular team sports: basketball (p<0.001, large effect size in basketball 1st league), handball and football (p<0.05, both small effect sizes). Players born in January were 3.23- and 2.89-times more likely to play in the 1st leagues than those born in December, for boys (football) and girls (basketball) respectively. In the overall analysis and in the remaining sports, presence of RAE was negligible. Therefore, the date of birth does not seem to be a constraint to participating in most sports in Bizkaia. The potential mechanisms for RAE are multifactorial and complex, yet a combination of factors, such as the popularity of a sport and the depth of competition, physicality and social influences may be involved. We discuss these mechanisms and potential measures to mitigate RAE.


2021 ◽  
Vol 15 (2) ◽  
pp. 50-60
Author(s):  
Roman Koloničný

The issue of the Relative Age Effect (RAE) has been long researched, discussed and published both in the academic and coaching community and the number of studies on it in various sports has significantly grown in recent years. The aim of this study was to verify the existence of RAE among Czech male (n = 6552) and female (n = 4131) junior tennis players and to identify possible differences in birthdate effect between male and female players. The research was carried out in players registered in the years 2007–2016 in the U14 age category in Czech Tennis Association (CTA) database; the athletes were divided into three subgroups (‘Ranked’, ‘Top 100’, ‘Top 10’). Research data were analysed by the methods of descriptive and inferential statistics: relative and absolute frequency, chi-square goodness of fit test () and chi-square test of independence () with the use of effect size (ES index w). A declining tendency of frequencies from Q1 to Q4 between male and female junior players was proven in all three subgroups.In the whole period of 2007–2016, a significant and strong RAE was demonstrated only in the ‘Top 10’ male subgroup (RAE was significant and ES was small or trivial in the other two subgroups). Among the female players, RAE was significant in all three subgroups (ES was small or trivial). Gender differences in RAE in favour of male players were significant in ‘Top 100’ and ‘Ranked’ (ES was small or trivial in all three subgroups). In the short and long term, RAE can have significant implications for the sport development of athletes; both coaches and the professional public can therefore be recommended to pay attention to this issue. The impact of RAE in sport, i.e. the uneven distribution of athletes’ birthdates, is more pronounced especially among junior athletes and often significantly affects their sports development and career.


1999 ◽  
Vol 16 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Jochen Musch ◽  
Roy Hay

Previous findings of skewed birth date distributions among sports professionals have been interpreted as evidence for a systematic discrimination against children born shortly before the cut-off date for each age grouping. Alternative explanations for these findings exist, however. This research therefore attempted to replicate the effect in a cross-cultural comparison. A strong relative age effect in professional soccer was found in Germany, Japan, Brazil, and Australia, showing that the effect is independent of different cut-off dates and a variety of climatic and sociocultural factors. A shifted peak in the birth date distribution of Australian soccer professionals paralleling a corresponding change in the cut-off date in Australian soccer in 1989 was also established. This pattern of results provides strong evidence for the cut-off date in youth soccer as the main cause for the relative age effect in professional soccer.


Sports ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 38 ◽  
Author(s):  
Göran Gerdin ◽  
Marie Hedberg ◽  
Carl-Axel Hageskog

2017 ◽  
Vol 60 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Alba Práxedes ◽  
Alberto Moreno ◽  
Luis García-González ◽  
David Pizarro ◽  
Fernando Del Villar

Abstract The Relative Age Effect (RAE) in sport has been targeted by many research studies. The objective of this study was to analyze, in amateur clubs, the RAE of soccer players, according to the sport expertise level of the team (e.g., A, B, C and subsequent) that they belong to within the same game category. 1,098 soccer players in formative stages took part in the study, with ages varying between 6 and 18 years old (U8 to U19 categories). All of them were members of 4 Spanish federated clubs. The birth dates were classified into 4 quartiles (Q1 = Jan-Mar; Q2 = Apr-Jun; Q3 = Jul-Sept; Q4 = Oct-Dec)according to the team they belonged to. The results obtained in the chi-squared test and d value (effect size) revealed the existence of RAE in the teams with the highest expertise level, “A” (X2 = 15.342, p = .002, d = 0.4473) and “B” (X2 = 10.905, p = .012, d = 0.3657). However, in the lower level teams, “C and subsequent”, this effect was not observed. Present findings show that players born during the first months of the year tend to be selected to play in teams with a higher sport expertise level of each category, due to their physical maturity. Consequently, this causes differences in terms of the experience they accumulate and the motivation that this creates in these players.


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