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

Abstract

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.