Push and Pull Factors: Contextualising Biological Maturation and Relative Age in Talent Development Systems

Relative age and biological maturity-related selection biases in male youth soccer across different competitive levels within a national association

OBJECTIVES AND METHODS

This study aimed to examine whether biological maturation and relative age selection biases existed and varied by level of competition (regional, national, and international) in Under-15 soccer players (n = 951) within the Swedish Football Association's male player pathway. A secondary aim was to examine the relationship between relative age and body height, body weight, predicted adult height, percentage of predicted adult height (PAH%), maturity Z-score, and biological age to chronological age offset.

RESULTS

The results showed a significant bias (p < 0.001), ranging from trivial-to-small in favour of relatively older players, with the most notable increase between the regional and national levels. There were also significant moderate-to-large biases in favour of early maturing players (p < 0.001), increasing in magnitude with levels of competition. PAH% (p < 0.001) and body weight (p = 0.014) showed the strongest differences across selection levels, where the bias compared to regional level was 0.23 standard deviations (SD) for PAH% at national level and 0.41 SD at international level, while body weight appeared to be particularly related to international team selection (0.36 SD in bias). Relative age showed a moderate positive correlation with PAH% (r = 0.38), but only trivial correlations with all the other biological and physical variables examined (r=-0.05-0.11).

CONCLUSIONS

The lack of association between relative age and the estimates of biological maturity timing and the additional physical characteristics suggests that relative age and biological maturity are distinct constructs. We encourage critical examination of how associations select young players for national talent programmes; current practices significantly diminish the chances of selection for those who are late maturing and relatively younger.

Exploring the existence, strength, and independence of relative age and maturation selection biases: a case study in Gaelic football talent development programmes

BACKGROUND

Biological maturity and relative age player selection biases are well documented in youth sports. However, there has been limited examination of the relationship between these biases.

AIM

This study investigated the presence, strength, and independence of relative age and biological maturity selection biases in Gaelic football.

SUBJECTS AND METHODS

A total of 247 male players from U14 to U16, from two talent academies were assessed for relative age (decimal age (DA)) and biological maturity (discrepancy between biological and chronological age (BA-CA)).

RESULTS

Relative age effects (RAE) were observed in the U14 (DA = 0.62, d = 0.40) and U15 squads (DA = 0.57. d = 0.26) only. A bias towards advanced maturity status was present at U14 (BA-CA = 0.60, d = 0.83), U15 (BA-CA = 0.78, d = 0.89), and U16 (BA-CA, d = 1.01). There was a trivial (U14, r(83) = -0.210; U15, r(88) = 0.060) and low (U16, r(76) = 0.352) correlation between relative age and maturity status.

CONCLUSION

Substantial maturity selection biases and, to a lesser degree, relative age biases are evident in youth Gaelic football. Critically, these biases are independent constructs. Coaches and policy makers should be educated on the distinct influences of relative age and maturation, and on strategies to address these biases.

Prospective and Retrospective Analysis of the Sporting Success of Elite Spanish High and Long Jumpers

The aim of the present study was to analyze the sporting progression from U14 to senior categories of elite Spanish high and long jumpers. For prospective analysis, 300 athletes ranked top 20 at U14 were analyzed (153 female and 147 male). For retrospective analysis, 64 athletes ranked in the top 20 in the senior category were included (21 female and 43 male). Ranking positions were registered in each of the seasons where they presented records. Only 6.3% (19) of athletes who reached the top 20 at U14 became successful senior athletes [4.7% (14) of athletes maintained top 20 status throughout their sporting careers from U14 to senior]. The transition rate from U14 to U16 (35.7%) was the most severe drop down in consecutive categories (after this, it ranged from 47.8 to 66.7%). Of the senior top 20 athletes (64), most of them were already ranked top 20 at U16 (59.4%, 38), at U18 (62.5%, 40), at U20 (70.3%, 45) and at U23 (78.1%, 50). Nevertheless, only 34.4% (22) were top 20 when they were U14 athletes. Transition rates in the top 20 senior athletes ranged from 86.7 to 95.5%. Around one out of four (26.6%, 17) of the top 20 senior athletes maintained top 20 status throughout their sporting careers from U14 to the senior category. Although early success is not a good predictor of senior success, successful senior athletes excelled early on and were able to remain in top rankings throughout their sporting careers of national elite jumpers.

International selection and competition in youth sport: pin the tail on the donkey or targeted intervention?

Across sporting contexts, there is growing debate surrounding the utility of junior international age group selection in sport. In this regard, there has been considerable focus on the age of selection, with the low conversion of athletes from junior to senior international level often used to critique the efficiency of such programmes. In this perspective article, we argue that there is a need for a more nuanced consideration of the effectiveness of international age groups in talent systems. We begin this perspective article with a synthesis of the literature pertaining to junior to senior transitions in sport, followed by the implications and opportunity cost presented by international age groups. We argue for a more contextual evaluation of international age groups relative to the performance aims of a talent system, the need for manipulation of challenge dynamics, and the resource costs of doing so (e.g., providing developmental challenges for those who have early advantage, or spreading resource amongst greater numbers for broader impact). We suggest that talent systems evaluate the opportunity cost presented by international age groups, with decisions based upon individual strategic context.

The measurement, tracking and development practices of English professional football academies

Tracking and measuring elements of performance is a well-established feature of practice in football academies. Player characteristics are considered, tracked, and measured using a variety of methods, with curricula often devised based on perceived importance and data interpretation. Against this breadth, our aim was to investigate the policies and systems in place at category one and two English football academies. Specifically, our objectives were (a) to understand what factors academies believe are important in the development of their players, (b) explore what academies are tracking and how they measure performance, and (c) analyse the extent to which these factors are integrated into the player's curricula. A total of 15 participants with over 10 years' experience across 40 Talent Development (TD) environments were recruited to participate in semi-structured interviews. Using Reflexive Thematic Analysis (RTA), generated themes suggest that academies perceive a differential weighting between performance factors, with greatest importance placed on technical, tactical and psychological factors. A lack of clear measurement systematisation was often apparent. Finally, we identified methods of player curricula integration. We conclude by offering implications for academies to optimise integration of systems and processes that measure and track their players development.