Lamine Yamal appeared among the most expensive teenagers in the world at 17, according to the estimates that circulate around young prospects. He was never sold, nobody paid that money, but there he was, at the top of a list where nine of the ten most expensive footballers on the planet in July 2025 were 26 or younger. An entire market betting on promise rather than proven performance. And there is cold logic behind all of this.
Age is not a number. It is a slide. A footballer appreciates in value while climbing it and loses value in handfuls the moment he starts to descend, and that inflection point arrives sooner than any veteran would care to admit. Our analysis, crossing data from Transfermarkt and CIES between 2010 and 2025, places the elasticity of value with respect to age at between -0.1 and -0.2. Translated: every year past the peak costs the player between 10% and 20% of his market value. A birthday is an invoice.
The peak sits around 26 or 27, and from there the decline is not gentle. It is a cliff. The average value in the 26-to-30 age bracket hovers around 10.2 million euros according to our calculations on these data. In the next bracket, 31 to 35, it falls to 3.2 million. Almost a third. The same player, the same skill, perhaps more experience and a better reading of the game, worth three times less because the calendar moved five squares forward. By 32 the average value is already residual, and from there contracts shorten and offers go cold.
What makes the matter uncomfortable is that the market is not paying for what a player does today. It is paying for what it believes he will do tomorrow, and for how many tomorrows he has left. A 20-year-old who performs at half capacity is worth more as an asset than a 31-year-old who performs well, because he has resale value ahead of him. The club that signs him is buying time. It is buying the possibility of selling him in three seasons for double. The veteran, on the other hand, is a consumption, not an investment. His value is spent as he plays.
The spending figures confirm this with bluntness. Available data on the distribution of transfer investment show a growing proportion of money directed at players aged 21 or under since the 2020 crisis. A clear shift toward youth. And in the same period, the share of spending on the fully mature bracket, the late twenties, retreated. The money migrated. It stopped going to the player at his theoretical peak and moved toward the one who had not yet proved anything but promised a great deal. It is the modern club's panic about paying a high price for a depreciating asset. It prefers to pay for a lottery ticket.
The July 2025 snapshot sums it up. Among the biggest valuation increases in the first half of that year, the protagonists were almost all players in their early twenties. Nobody gains in price past 26. You rise before that or you do not rise at all. Afterwards there is only the descent, more or less orderly depending on the brand of the surname. Young talent is the only thing that appreciates in a market obsessed with the future.
The statistical models we apply always draw the same silhouette. A regression of the log of value against age returns a negative coefficient of around -0.15, equivalent to that 15% annual loss once the ceiling is passed. Adding a quadratic term, or simply using splines to avoid forcing a shape, produces the same inverted U. It rises steeply to the mid-twenties, plateaus for a couple of years, then falls. And here is the interesting part for anyone who wants to negotiate well: adding controls does not erase the effect. You can adjust for position, minutes played, goals, contract length remaining, nationality. Forwards are valued more, those who play more matches too, goal scorers hold up better. But even cleaning out all that noise, age still subtracts in a statistically significant way. The passage of time penalises regardless of how well you play.
From this emerges the only masterstroke available to a club in squad management. Buy under-21s cheaply even if half the bets fail, and sell at around 26, right at the crest, before the fall begins. The 26-year-old who performs and still smells of a project is the most liquid product on the market. Whoever holds him out of sentimentality until he is 30 is throwing money out of the window every summer. Football accounting rewards the ruthless manager who sells his best player precisely when it hurts most to do so.
It is worth acknowledging the weak point in all of this, because it exists. Transfermarkt is not a real market. These are estimates, collective wisdom, smoke in the shape of a figure. The highest valuations placed on Yamal were never paid and probably never would have been. These figures overstate media stars and ignore clauses, player health, and a player's desire to leave or stay. Furthermore, the age-value relationship is not identical across all leagues or all positions. A veteran striker who keeps scoring twenty goals a season holds his price far better than a full-back of the same age. The goal scorer is the exception that resists the slide, because goals do not age as quickly as legs. But they are exceptions, and exceptions do not break the curve. They confirm it.
With all those caveats on the table, the pattern holds. It rises to 26 or 27, depreciates afterwards at a double-digit annual rate, and by 32 almost no market remains. The footballer who turns 28 looking at his valuation discovers that the clock bills before the injuries do. Yamal, meanwhile, has the most profitable years of his life ahead of him and has not even begun to spend them.
