National Football League players have a strange earnings pattern. They make a ton of money up until the age of 30 or so, then have much lower income for the rest of their lives—the opposite of most workers. A player who makes it through six years in the NFL earns more than a typical college graduate does in a lifetime. But they go bankrupt more often, and more quickly, once they retire.

Researchers from the California Institute of Technology, the University of Washington, and George Washington University took a look at all NFL players drafted from 1996 to 2003, from their entry to the league up to their first 12 years after retirement, to find out more about when those bankruptcies occur.

Here, from their new National Bureau of Economic Research working paper, is the researchers’ model of a median NFL player income profile:

Carlson et al.

An NFL player with a median-length career earns about $3.2 million, according to this sample. If he saves a large amount for retirement, he would have little risk of bankruptcy.

Here’s the evolution of NFL player bankruptcy over time. Active players almost never declare bankruptcy. But quite a few are bankrupt just two years after retirement. And the rate accelerates over time. Even the most conservative estimate predicts that about 15% of all NFL players will have declared bankruptcy within 25 years after retiring. The median model predicts that more than 20% will:

Carlson et al.

Overall, career earnings and length have barely any effect on the risk of bankruptcy. Even highly successful players with long, well-paid careers go bankrupt. The researchers estimate that it would take $14 million in extra career earnings for an NFL player to cut his bankruptcy risk in half.

Also, the authors aren’t exactly sure why, but bankruptcy rates spike for players who spent exactly five years in the league:

Carlson et al.

Rookie contracts typically last four years, so a five-year career means that someone was in the league long enough to perhaps expect several more years of high pay. But players tend to substantially overestimate their earnings potential, overspend in the near term, and underestimate the risk of injury or dropping out of the league.

That spike in year five might be from players who made it just one year beyond their rookie contract. Or it could come from players who got injured while under contract for a small amount of guaranteed money. (The researchers say they plan to investigate this in future work.)

Either way, if you never make it past the rookie contract, you are less likely to be able to afford truly extravagant spending, and have more time and motivation after leaving the NFL to find another career.