The aim of this study is to test the presence of the relative age effect (RAE) and to examine height in an overall population of the young French basketball players from 7 to 18 years old, male (n=151 259) and female (n=107 101). For the boys as for the girls, the results show a statistically significant RAE in all age categories. The effect seems more pronounced during puberty. As far as the height is concerned, players born during quarters 1 and 2 are always significantly taller than those born during quarter 4, apart from the 17-year-old female players. These results require a new look at the methodology in the statistical calculation and the interpretation of RAE. A study wanting to give a precise measurement of this effect will have to take as the expected theoretical distribution the whole population of licensed players in the corresponding years, rather than one on the global population of the country. This will avoid the hasty conclusion that an asymmetric distribution of dates of birth of professional players would be due to RAE, whereas in reality it would be representative of one existing in the population of licensed players.

The aim of the current research was to investigate the relative age effect (RAE) as a factor of basketball dropout. In order to do so, we examined the distribution of birth dates of young male (n=44,498) and female (n=30,147) French basketball players who have dropped out this sport during or at the end of the 2005-2006 season. χ(2) analyses showed an underrepresentation of dropouts among male players born early in the competition year and an overrepresentation among those born late in the "9-10 years old,""11-12 years old," and "13-14 years old" categories and in the first year of the "15-17 years old" category. Concerning girls, this asymmetry was observed across the same age categories. For both boys and girls, there was no biased distribution in the "7-8 years old" category. Findings of the present study confirm that the RAE should be taken into consideration in studies about sport dropout as a variable that may influence this phenomenon significantly.

The aim of this study was to examine the birthdates distribution of French male soccer players (n = 363,590) who dropped out during or after the 2006-2007 season, to test whether the Relative Age Effect (RAE) is linked to the dropout behaviour. An over-representation of players born late in the competitive year was found among dropouts, from the U9 to the U18 age categories, whereas their counterparts born earlier in the year were under-represented.The distortion of the distribution was particularly important for the extreme quarters of the competitive year, and in the U13 and U15 categories. This biased distribution was however not confirmed regarding the U7 category. Finally, regarding the adult category, an unbiased distribution of dropouts was found as hypothesized. Practical implications to avoid the negative consequences of RAE are advanced.-3 -