Children born early in the selection year can be almost a year older than teammates born late in the same year. In childhood that difference is physically huge.
The consequences:
Academy squads are heavily skewed towards players born in the first months of the year
Talented late-born or late-maturing children can be dropped early
Early maturers stand out now, but that doesn’t always predict adult success
A quick check for coaches: list your squad’s birth months. If January to March births clearly dominate, it may be worth looking at how players are selected.