The absence of changes in the relative age effect present an opportunity for lower income soccer clubs to be more efficient than Europe’s elite. [Dataset]

Abstract

Youth soccer leagues chronologically match children based on their birth year with the aim of matching developmental milestones to ensure fair competition. An overrepresentation of athletes born earlier in the year compared with those born later in the year is known as the relative age effect (RAE). This may be in part due to a physical selection bias for example increased stature, muscle mass, sprint speed etc in older children. The selected children enter talent development systems earlier relative to their age (e.g., two U11 players entering at the same time may contain a December born player who is 12 months younger than a January born player although both are beginning their academy journey during the same section period) and gain higher degrees of exposure to coaching, physical training and competition at a younger age which in turn can lead to an improvement in technical and tactical abilities at older ages. Although this primarily relates to physical advantages as older players are assessed against their younger peers and leads to improvements in physical performance associated with the impact of stature and muscle mass this also impacts sociological and psychological advantages. The RAE expresses itself with the increasing competition level in youth soccer, and impacts coaches' subjective measures of player ability, with these subjective measures of ability being the determining factor of inclusion and exclusion in a soccer academy. The effects of RAE bias persist through to senior/adult level and could influence the judgement of decision makers explaining increased dropout of players who have not yet fulfilled their potential.

Citation

CRAIG, T.P., ENRIGHT, K., MAUGHAN, P., ABBOTT, W. and NAVARRO, J.F. 2025. The absence of changes in the relative age effect present an opportunity for lower income soccer clubs to be more efficient than Europe's elite. [Dataset]. PLoS One [online] 20(5), article number e0323971. Available from: https://doi.org/10.1371/journal.pone.0323971.s001

• Acceptance Date: Apr 16, 2025
• Online Publication Date: May 20, 2025
• Publication Date: May 31, 2025
• Deposit Date: May 29, 2025
• Publicly Available Date: May 29, 2025
• Publisher: Public Library of Science
• DOI: https://doi.org/10.1371/journal.pone.0323971
• Keywords: Sports; Age groups; Finance; Anthropometry; Running; Analysis of variance; Children; Sports science
• Public URL: https://rgu-repository.worktribe.com/output/2849187
• Related Public URLs: https://rgu-repository.worktribe.com/output/2848598 (Journal article output)
• Type of Data: XLSX file.
• Collection Date: May 3, 2024
• Collection Method: A retrospective analysis of 512 male academy players (from 2005–06 to 2016–17) from the Scottish Academy of a professional club was completed. Players from U11 to U17s were assessed for physical performance characteristics and relative age effect impact. The academy held "elite" categorisation from the Scottish FA's Club Academy Scotland criteria. Participants were tested at the same location, on the same surface at the same time of day throughout the period investigated. An initial measure of stature to nearest 0.1 cm (SECA Height Measure, Hamburg, Germany) and body mass to 0.1 kg (SECA floor scale, Hamburg, Germany) was taken by an ISAK accredited anthropologist prior to a group standardised warm up. The greatest counter movement jump height (CMJ) of three repetitions from a self-selected counter movement depth was recorded to 0.1 cm (MuscleLab IR Jump MAT, Ergotest, Langonsund, Norway). Prior to the sprint protocol, participants completed 3x15m warm up runs (1x80%, 1x90%, 1x100% perceived maximum) followed by 3x20m maximal efforts with split times recorded to the nearest 0.01s at 5m, 10m and 20m (Speed Trap Timing, Brower Timing Systems, Utah, USA). The fastest 20m time and the associated 5m and 10m splits times were recorded for analysis. Sprints began 1m behind the 0m timing gate, were initiated with one foot self-selected in front of the other with a minimum of a 1:10 sprint: recovery period between the 3 trials. Following a ten minute recovery period, participants performed the YYIR1 test in groups that were set based on their previous YYIR1 results with test termination and final "score" following the recommended criteria. Data were analysed using R statistical software. A one-way analysis of variance (ANOVA) was performed to assess the impact of time and evolution of RAE changes across the seasons recorded. When the ANOVA indicated significant differences, post hoc comparisons were conducted using the Bonferroni correction to control for Type I error across multiple comparisons