The influence of biological maturity status on the German talent pathway in youth elite soccer: Insights into selection biases, differences in playing positions and team performance within national selection tournaments

Differences in biological maturity status (BMS) during puberty may advantage biologically older players within selection processes. This study examined maturity-related differences across multi-stage selection procedures, playing positions, and the relationship between BMS and team performance within the German Football Association's U15 national selection tournaments. Anthropometric measurements were collected from N = 695 male regional association team players (M = 14.1 ± 0.3 years), and BMS was assessed via skeletal age using the BAUSport™ ultrasound device. When compared to players' expected BMS, a significant large pre-selection bias was observed favouring players with higher BMS to get selected for a regional association team (M = 15.1 ± 1.0, d = 1.19, p < .001). Positional analyses revealed significant differences in BMS (η² = .14, p < .001) with goalkeepers, defenders, and forwards being biologically older than midfielders. Team performance (points achieved) showed a strong positive correlation with BMS (rs = .71, p < .001). Significant small advantages in maturity-related variables were found for players selected for the extended U15 youth national team squad (0.17 ≤ d ≤ 0.23; p < .05). Position-specific analysis of selection status revealed medium-to-large effects in forwards and goalkeepers with respect to BMS. The findings highlight the critical influence of BMS in multi-stage selection processes and underscore the need for position-specific considerations to ensure fair and developmentally appropriate talent promotion.