Your football future could be decided before you ever kick a ball. The Relative Age Effect is a phenomenon where the calendar, not your talent, might determine your success.
The Relative Age Effect occurs, when individuals born earlier in the selection year have a developmental advantage. In school, for example, students born in September outperform those born in July, particularly in early years. In football, this often translates to January – the cutoff point for most football academies in Europe, giving older players a head start against their younger peers. Because relatively older athletes may have physical, physiological, or psychological advantages over their younger peers, coaches tend to focus more on them, leading to a selection bias. This attention grants these players more opportunities for advanced coaching, and competition. This could, in the long run, contribute to these selected players being more technically and tactically skilled than their non-selected, younger peers, who are replaced and excluded from this process even though they may have been equally or even more talented in football.
To see the significant impact of the Relative Age Effect in football, look at the chart below. It highlights the distribution of player births by month across the top 5 European leagues for the 2024/25 season.
As you can see, there’s a significant imbalance in the distribution of player birthdays. A staggering 13% of all players are born in January—equal to the combined total of November and December. The data also reveals a steady decline throughout the year, with nearly one-third of all players born in the first quarter. This shows how players born earlier in the year gain a distinct advantage over their younger counterparts, reinforcing the impact of the Relative Age Effect in football.
English Premier League vs Rest of Europe
The cutoff date for player selection in football academies across most European countries is January 1st. This means, players born earlier in the year often benefit from being more physically and mentally mature than their peers. However, in England, the cutoff date is September 1st, which explains why the Premier League follows a different pattern then the other Top 5 Leagues. Here, the Relative Age Effect is less pronounced, because homegrown players are more often born in the later third of the year. While this is visible in this graph below, the league’s global nature and financial power bring in mature international players, slightly skewing this effect.
Positional Differences
After analyzing the differences between birth months and the Relative Age Effect, another crucial factor comes into play – player positions. The physical demands of certain positions amplify the advantages of being born earlier in the year, particularly in youth football.
Defenders, for example, often need to be taller, stronger, and more physically imposing. This gives January defenders an advantage especially during development stages. Players born earlier in the year, who are typically more physically mature, are more likely to excel in these positions, gaining an edge in selection.
Forwards, on the other hand, do not rely as much on size or physicality. Speed, dribbling, agility and creativity are key, making smaller, more agile players valuable—especially in wide positions like wingers. While strikers can benefit from strength to win headers and hold off defenders, quick and nimble forwards can thrive regardless of size. This explains why the birth months of attackers tend to be more evenly distributed, especially compared to the defenders.
Tackling the Relative Age Effect
There are already several approaches how to counteract the Relative Age Effect. One effective strategy, that is already mentioned in this Guardian article, is grouping players by age and not by year of birth. For example, the oldest 10-year-old may have an advantage, but once they turn 11, they become one of the youngest in their group and have to compensate this with their footballing skill. This allows players to experience both perspectives, reducing long-term disadvantages and helping identify top talents earlier, regardless of their birth date.
Another solution that is frequently discussed is the implementation of age quotas. This system would require teams to have an even distribution of players born in each month, ensuring that athletes born in December are not disadvantaged compared to those born in January. The idea is to level the playing field, giving all players the same opportunities.
However, age quotas can trail some challenges. The coaching staff may face difficulties in fairly distributing talent, as some birth months may naturally have fewer talented players then others. Additionally, such quotas could lead to forced selection, where less deserving players are chosen simply to meet the quota, potentially compromising overall team quality.