The tall kid gets to dribble too.

Almost every U12 team has that kid: a head taller than everyone else. Under the basket, they grab every rebound and make every layup. That wins games. But it comes at a cost you only notice years later.

In youth basketball, kids born early in the year are clearly overrepresented. In France this showed across the entire youth basketball population of more than 250,000 kids, most strongly during puberty. Those born early were on average taller, heavier and stronger (Delorme & Raspaud, 2009). In a Spanish study, about two thirds of the selected youth players were born in the first half of the year, and the selected players were physically more mature (Torres-Unda et al., 2013). So selection often picks not the greatest talent but the biggest head start in development.

That head start is borrowed. When the others hit puberty, they catch up. Two large reviews of Olympic sports show how little early success says about later on: performance as a junior explains only a little over two percent of later performance as an adult (Barth, Güllich, Macnamara & Hambrick, 2024). And about nine out of ten internationally successful U17 and U18 athletes did not make it to the international top as adults (Güllich, Barth, Macnamara & Hambrick, 2023).

What does that mean for the gym? The tall kid who plays with their back to the basket at twelve doesn't learn to dribble under pressure, doesn't learn a shot from distance and doesn't learn to play on the perimeter. At sixteen the others are often just as tall, and then exactly those skills are missing. That is why USA Basketball explicitly recommends teaching position concepts at the foundational level but not assigning positions to kids (USA Basketball, Youth Development Guidebook). In German mini-basketball, man-to-man defense is mandatory and double-teaming is not allowed. Every kid has to win their own matchup (German Basketball Federation, mini-basketball rules).

Getting out of the comfort zone doesn't mean overwhelming kids. Learning needs the right level of difficulty, more on that in the article "Brave, not flawless." For the tall kid that means: bring the ball up the court sometimes. For the small girl who already dribbles well: go inside sometimes.

For parents: if your kid is the tallest today, enjoy it and make sure they still learn everything. If your kid is the smallest today, that's a snapshot.

Our theses

1. A head start in development is not talent. It is borrowed.
2. A kid who only plays to their strength at twelve often has only that one strength at sixteen.
3. Youth coaching is measured by the players it has at eighteen, not by the U12 standings.

Sources

• Barth, M., Güllich, A., Macnamara, B. N. & Hambrick, D. Z. (2024). Quantifying the extent to which junior performance predicts senior performance in Olympic sports: A systematic review and meta-analysis. Sports Medicine, 54, 95–104. doi:10.1007/s40279-023-01906-0 (opens in a new tab)
• Delorme, N. & Raspaud, M. (2009). The relative age effect in young French basketball players: a study on the whole population. Scandinavian Journal of Medicine & Science in Sports, 19(2), 235–242. doi:10.1111/j.1600-0838.2008.00781.x (opens in a new tab)
• German Basketball Federation (Deutscher Basketball Bund). Spielregeln Minibasketball Deutschland (mini-basketball rules, in German). basketball-bund.de (accessed September 29, 2026).
• Güllich, A., Barth, M., Macnamara, B. N. & Hambrick, D. Z. (2023). Quantifying the extent to which successful juniors and successful seniors are two disparate populations: A systematic review and synthesis of findings. Sports Medicine, 53(6), 1201–1217. doi:10.1007/s40279-023-01840-1 (opens in a new tab)
• Torres-Unda, J., Zarrazquin, I., Gil, J., Ruiz, F., Irazusta, A., Kortajarena, M., Seco, J. & Irazusta, J. (2013). Anthropometric, physiological and maturational characteristics in selected elite and non-elite male adolescent basketball players. Journal of Sports Sciences, 31(2), 196–203.
• USA Basketball. Youth Development Guidebook, p. 18.

As of September 29, 2026