Análise do efeito da idade relativa em copas do mundo de futebol sub-17

Abstract

This study aimed to verify the relative age effects (RAE) in U-17 World Cups and which positions may be receiving the most influence from this phenomenon. Birth dates of 1011 football players who participated to the 2015 and 2017 editions of U-17 Football World Cup were collected. Birth dates were organized quartiles Q1 (January, February, March), Q2 (April, May, June), Q3 (July, August, September) and Q4 (October, November, December). The analyzes were carried out taking into account the positions of the players: defenders (defenders and full-backs), midfielders (defensive midfielders and attacking midfielders) and forward (wing and center forward). Analysis of absolute and relative frequency of the quartiles was realized. The chisquare test (χ 2 ) considered as significant values of p<.05 and were used the Bonferroni correction for multiple comparisons between quartiles. In addition, the effect size was calculated to indicate the magnitude of the effect in each comparison between the quartiles. The results show that the RAE is present in the competitions analyzed and that the distribution of birth dates by position follows the general distribution pattern. It is concluded that there is a preference to select football players born in the first quartile of the year to make the selections in the Under-17 Football World Cups.