In theory, it’s such a simple concept. In practice, it’s been impossible for any player to get it.
To protect a player who signs a long-term deal against the contract becoming obsolete, the player gets a guaranteed percentage of the salary cap in every year of the contract.
Multiple teams have tried to get that term. A decade ago, former Jets cornerback Darrelle Revis tried to get that term. The team refused. Quarterback Kirk Cousins, while under the franchise tag in Washington, tried to get that term. The team refused.
Per a source with knowledge of the situation, Seahawks quarterback Russell Wilson has tried to get that term. The team refused.
It’s unknown whether Chiefs quarterback Patrick Mahomes tried to get a percentage of the salary cap. Before committing to a 12-year contract, he should have insisted on it. And if Mahomes can’t get that term, can anyone?
Here’s what it will take: A franchise quarterback or rare talent at another position hitting the open market unfettered, having three or more viable candidates, will have to insist on the term as essentially a price of admission to the auction. Even then, there’s no guarantee it will happen.
Many believe that the NFL’s Management Council doesn’t want to cross this bridge, because it removes the cost certainty that otherwise exists in every year of a player’s contract. Thus, even though it’s a permissible device, teams aren’t doing it. (Technically, if the Management Council is preventing teams from doing it, that’s collusion. But good luck proving it.)
Eventually, it needs to happen. It already should have happened, especially with the Mahomes deal. Maybe it will eventually happen, if a franchise quarterback refuses to accept long-term offers, plays out his rookie deal and a couple of franchise tags, and then dictates his terms to the cluster of clubs clamoring to sign him.