###### Abstract  
This study investigated the relative age effect (RAE) in junior padel players participating in the 2024 European Junior Championships by Teams. The sample included 285 athletes (165 boys from 16 boys' teams and 120 girls from 12 girls' teams). Dates of birth were categorized into quartiles, and data analysis employed Chi-squared goodness-of-fit tests, [PERSON]'s exact goodness-of-fit tests, Chi-squared tests, [PERSON]'s exact tests with Monte Carlo correction (95% CI), and Spearman correlations. The results showed no consistent RAE overall. However, in boys, players born in Q1 (CSR = 2.2) and in the last year of eligibility (CSR = 2.0) were more prevalent in higher-ranked teams. Position directly correlated with quartile (boys: \(p=0.015\); girls: \(p=0.001\)) and category year (boys: \(p=0.032\); girls: \(p=0.038\)). These findings suggest that while RAE was not observed across all junior padel players, boys' teams, particularly in higher ranks, exhibited trends favoring early birth quartiles and the final year of eligibility. Such patterns may influence competitive performance and talent identification. Further research is needed to understand the implications of RAE in youth sports, particularly regarding talent development and team selection processes. Academic Editor: [PERSON]  
10 December 2024 30 December 202  
gender--the selection process is fierce. Only the most talented and fortunate athletes are chosen to compete, making the national team a symbol of elite status within the sport. However, beneath the surface of selection processes in youth sports lies a subtle yet significant factor: the relative age effect (RAE). This phenomenon arises from age differences among individuals within the same nominal age group, often due to their birth in different quartiles of the same year [6]. These differences sharpen disparities in athletes' maturation status, which may not align with their chronological age [7]. As a result, athletes born earlier in the year--often with advanced maturational development--are overrepresented in youth sports [8]. This advantage, commonly referred to as the relative age effect, gives relatively older athletes more opportunities for selection and better performance outcomes compared to their younger peers [9]. It is important to note that, in padel, players nearly four years apart in age could be eligible for the same spot. For example, a Spanish boy born on 1 January 2008 and another born on 31 December 2012 could both vie for a place on the U16 Spain team if the competition was held in 2024. Moreover, according to the rules, one player could compete in one match within their own category and, in another match, be allowed to compete in an older age category. RAE has been investigated from various perspectives and for diverse purposes. Research has explored its prevalence in both team and individual sports [10, 11, 12], assessed its influence within specific competitions [13, 14], and examined the extent to which factors such as gender, age, or competition categories in clubs and federations shape its impact [15, 16]. Moreover, some studies have proposed interventions aimed at mitigating its potential consequences [17, 18, 19]. Recently, there has been a growing focus on understanding the relationship between RAE and competition performance, with the aim of gaining deeper insights into how this phenomenon influences athletic outcomes [20, 21, 22]. Yet, in the world of padel, the impact of relative age remains largely unexplored territory. Despite padel's rapid rise, it is one of the least studied sports regarding RAE in recent years [23]. To the best of our knowledge, there has been only one study addressing this issue, and it focuses exclusively on professional players [24]. This gap is surprising given the sport's rapid growth and the increasing competition among youth athletes. Understanding how relative age influences national team selection in padel is crucial not just for fairness, but for unlocking the full potential of young athletes.