Key points are not available for this paper at this time.
Recent studies indicate that month of birth is related to achievement in a number of sports. Birth dates were collected for all players on teams competing in the 1990 World Cup and the 1989 Under-17s and Under-20s World Tournaments in Football. Results indicated that those born early in the "activity year" (August 1 through July 31 for football) were over- represented, while those born later were under-represented. The effect was particularly strong in the Under-17s and Under-20s tournaments. Results are interpreted in the context of the "relative age effect".
Barnsley et al. (Sun,) studied this question.