Relative Age Effects in Korean Football: Analysis of Age-Specific International Teams

Abstract

Purpose: This study aimed to identify relative age effects of South Korea national male football teams that participated in 38 international competitions in age-specific categories from 2000 to 2018; U-16 (n=176), U-17 (n=82), U-19 (n=198), U-20 (n=147), and U-23 (n=166). Methods: Available information on birth-dates, heights, and body weights of South Korean elite male football players was collected from the official websites. Chi-square test was conducted and odds ratios were calculated with 95% confidence interval in order to examine differences of quarter distribution between expected and observed subgroups. Results: The birth distributions observed in each team were significantly different than those expected in general population of the same age (U-16: χ 2 =59.364, p<0.05; U-17: χ 2 =36.829, p<0.05; U-19: χ 2 =51.697, p<0.05; U-20: