Influence of the Relative Age Effect on the Competitive Level and Playing Position of Male Japanese Elementary School Baseball Players

This study examined the in‰uence of the relative age eŠect (RAE) on the competitive level and playing position of male elementary school Japanese baseball players. The sample comprised the following: (1) 506 general male baseball players (BP) who were aged 11-12 (sixth grade) and who had not competed at the prefectural level and (2) 189 regionally selected players (SP) who were aged 11-12 (sixth grade) and who had been selected to compete at the prefectural level or a higher level. The subjects were divided into two groups based on their birth months (Semester 1 (S1): April-September and Semester 2 (S2): October-March). Prevalence ratio for each semester was calculated. Pearson's chi-square test was employed to examine the RAE of each group and each playing position. Results of a chi-square test at each competitive level showed that the SP group was statistically signiˆcant (S1>S2) but the BP group was not. The chi-square test for the pitcher and the ˆelder (catcher, inˆelder, and outˆelder) positions revealed statistical signiˆcance in the SP group (S1>S2), with only the pitcher position showing statistical signiˆcance in the BP group (S1>S2). The results indicated that the RAE was higher in more competitive level junior baseball players and that the RAE exerted a stronger in‰uence on the pitcher position than on the ˆelder positions.