The insights of the researchers can explain the riddle of way so many elite soccer players are born early in the year. Since youth sport are organised by age group. teams have a cut-off birth date. In the European youth soccer leagues, the cut-off date is December 31. So when a coach is assessing two players in the same age group, one born in January and the other in December, the player born in January is likely to be bigger, stronger, more mature. Guess who the coach will pick. He may be mistaking maturity for ability but once chosen, those January-born players are the ones who, year after year, receive the training the deliberate practice, the feedback -and have the accompanying self-esteem-that will turn them into elite players.