Dead cap in the NFL is just money that needs to be counted on the salary cap that has already been paid to the player. It is called proration when they are on the team and dead cap once they depart.
Since Joel Bitonio's contract recently expired with the Browns and left a $23.504m dead cap, it is worth looking at where this money came from. Each years cash is shown in a different color so that you can trace it through the contract.
The first really important part to note is that Bitonio is costing the Cleveland Browns $0 for the 2026 season unless he re-signs with the team, this is because cash is king.
This is the same contract, I have just colored the dead cap in red so that you can easily see it within the deal. It relates to payments made to Bitonio for the 2022, 2023, 2024 and 2025 season. Where option and signing bonuses are spread over five years in deals, you just need to account for this money into the future when the salary cap rises.
If he had decided to retire, they would have saved $14,930,000 on the 2026 salary cap. Rolled that money over into 2027 and then accounted for that same $14,930,000 in 2027 dead cap. While you need to push as much out as possible, one single deal isn't going to change the model in any way.
Viewing it as deferred accounting payments is potentially a better view or an analogy I like to use is paying for a holiday after you get home. You've had the benefit of Bitonio playing for you, this is just accounting for the bill in your ledger once it has passed.