The relative age effect in the Gaelic Athletic Association (GAA): a mixed methods approach

Background: In the Gaelic Athletic Association (GAA), Talent Academies (TAs) and senior teams cater for high-performing players. However, only two previous studies have quantified the relative age effect (RAE; i.e., a selection bias favouring those born near the beginning of the cut-off date) in these cohorts. Additionally, no studies have explored stakeholder understanding of the RAE using qualitative methods.

This study aimed to: (a) quantify the RAE in TAs and senior teams, and (b) investigate stakeholder perspectives of the talent development environment, providing practical insight into the RAE.

A mixed methods sequential explanatory study design was employed. Phase one involved a retrospective analysis of longitudinal data for the frequency and distribution of births using TA (n = 12,445) and senior (n = 8,752) players. Phase two comprised two focus groups of key stakeholders [coaches (n = 4) and Talent Development Leaders (n = 4)] at TA and senior level.

Analysis revealed a significant difference between TA birth quarter (BQ) distributions compared with expected distributions (P < 0.001; BQ1 = 30.4% vs. BQ4 = 17.6%), whereas at senior level, there were no significant differences observed (χ2 (df = 3) = 3.812, P = 0.282). In phase two, inductive analysis revealed three higher-order themes: (a) understanding of the RAE, (b) selection criteria, and (c) player characteristics.

The GAA are encouraged to reflect on the practice of chronological age band grouping, investigate possible solutions to limit the effects of the RAE, and offer support programmes to educate key stakeholders.