Beschreibung:
The relative age effect (RAE) is associated with (dis)advantages in competitive sports.While the RAE in elite male soccer reveals a skewed birthdate distribution in relation to acertain cut-off date, research of RAE in elite female soccer is affected by small numberof samples and conflicting results. The purpose of this study was to investigate theRAE in elite adult German soccer regarding gender and competition level. The samplecomprised 680 female and 1,083 male players of the two top German leagues duringthe 2019/20 season and German national teams (A-Team to Under 19). Differencesbetween the observed and expected birthdate distributions were analyzed using chisquarestatistics and effect sizes followed by calculating odds ratios. Results showeda statistically significant RAE with small effect size across all players included for bothgenders (female players: P < 0.001, W = 0.16, male players: P < 0.001, W = 0.23). Theidentified RAE was based on an over-representation of players born at the beginning ofthe year. According to gender and competition level, RAEs were more pronounced inGerman male soccer. While significant RAEs were found among males in the first twoleagues (first league: P < 0.001, W = 0.19, second league: P < 0.001, W = 0.26), theRAE of females was more pronounced in the second league (first league: P = 0.080,W = 0.16, second league: P = 0.002, W = 0.20). The analysis of RAE regarding thenational teams revealed a statistically significant RAE with large effect size for only theyoungest investigated age group of male players (Under 19: P = 0.022, W = 0.52).Our data show an RAE in female and male German adult soccer, which could beaccompanied by a loss of valuable elite players during the youth phase of the career.Consequently, the pool of talented players at the adult level would be limited.