Academy selection still rewards being born in September

The relative age effect has been documented for decades, everybody in youth development knows about it, and the intake data barely moves.

Line up the birth months of any national youth squad and the shape is the same everywhere. Heavy at the start of the selection year, thin at the end. Not slightly. In many programmes the first quarter supplies several times as many players as the last.

The mechanism is not mysterious. Group children by year of birth and the oldest in the group are up to twelve months further along, which at eleven or twelve is a large difference in size, speed and coordination. They perform better. They get picked. Being picked buys better coaching, more matches, stronger opposition and the belief that comes with being told you are good, and a year later the advantage that started as biology has been converted into genuine skill.

That is a feedback loop, and it is the kind that hides its own cause. By the time anyone measures the squad, the early-born really are better players. The selection looks correct because the selection made it correct.

What gets lost is not just fairness, although it is unfair. It is that the system is throwing away the children who would have been best at nineteen, because it filtered them out at twelve on a criterion that stops mattering entirely once everyone has finished growing. There is a well-known counterweight, sometimes called the underdog effect, where the late-born players who do survive tend to be unusually good, having had to compete against bigger opponents throughout. That is a compliment to the survivors and an indictment of the filter.

Fixes exist and none of them are hard. Rotate the cut-off date between age groups so the disadvantage does not follow the same children every year. Band by physical maturity rather than birth date for some competitions. Keep a quota of places for the last quarter of the year. Publish the intake distribution and let it embarrass people.

Almost nobody does any of it consistently, and the reason is that youth coaches are judged on results this season, and the biggest twelve-year-old wins games this season.

Change what the youth coach is graded on, or stop pretending the problem is not understood. It has been understood for forty years.