Talent development (TD) is a complex, dynamic, and non-linear process mediated by a range of biopsychosocial variables. However, research in TD has been dominated by retrospective and uni-disciplinary designs and a lack of applied focus. Adopting a biopsychosocial, pragmatic, and interdisciplinary lens, this PhD addressed gaps within the literature by critically examining the Football Association of Ireland’s (FAI) male TD system. Chapter three critically considered the research underpinning the early engagement practices of professional football clubs and the extent to which, and how, the pathway can provide the most appropriate starting point for player development. Evidence highlighted the need to consider the biopsychosocial nature of TD and socio-political environmental influences. Reflecting the environment, Chapter four examined the level of coherence across the FAI’s TD system. Findings demonstrated a lack of coherence, characterised by conflicting interests, a lack of communication, and poor relationships between stakeholders. Chapter five investigated the extent to which biological maturation and relative age selection biases existed across the national talent pathway. Large selection bias in favour of early maturing players were found, increasing in magnitude with age, with relative age biases smaller in magnitude and stable with age. Chapter six demonstrated that the magnitude of these biases varied significantly by playing position. Chapter seven examined the nature of biological maturation and relative age and their associated challenge dynamics in TD. Findings suggest that these concepts must be considered individually alongside a broader field of biopsychosocial factors that impact challenge dynamics. Chapter eight investigated the temporal impact of perceived challenges and psychological safety in players in the FAI’s national TD system. Significant biopsychosocial challenge was a key feature of each player’s experience, although the dynamic of challenge effects were highly individual. Findings from this thesis reflect the complex nature of TD, with practical guidelines for practitioners provided throughout.