Designating a player as a post-June 1 cut (which I think can be done with up to two players each season) allows the dead money to be split between two seasons. If Smith is cut and
not designated as a post-June 1 cut, then there's $17.4M in dead money on the 2024 cap. If he
is designated as a post-June 1 cut, then $8.7M of the dead money falls on the 2024 cap and the remaining $8.7M falls on the 2025 cap.
There is some real savings there, but it's not close to the $8.7M difference that shows up on OverTheCap's web pages. It's a little hard to calculate exactly how much, but it's a lot less. The savings come from an NFL-modified version of the "time value of money." There's the usual "I would gladly pay you Tuesday for a hamburger today" time value of money (a dollar you have today is worth more than a dollar you'll receive in a year), and that's increased by the fact that NFL salary caps are still rising, so taking $8.7M of the dead cap and pushing it back to 2025, when the cap is very likely be higher than in 2024, makes those $8.7M hurt just a little less.
Personally, I think the Seahawks' best move is to roll with Smith for 2024 while looking for some other guy who can be good but not great for a well-below-league-average QB cap hit ("the next Smith"), but that could change depending on other moves the Seahawks make. If the Seahawks
are going to cut Smith, they'll have to see if there are other players who would save them more by having a chunk of their dead money pushed back a year. I figure Jamal Adams is extremely likely to be so designated. In his case, it comes out to exactly half too, but the numbers are bigger. It's $20,833,334 of dead money if he's cut and
not designated as a post-June 1 cut, and it's half that in 2024 and half in 2025 if he
is. The $16.5M in 2024 cap savings by designating him as a post-June 1 cut will help a lot. The Seahawks won't need to use a post-June 1 designation on Diggs or Dissly, but I fully expect both of them to be gone (or Dissly possibly renegotiated).
EDITED TO ADD: @renofox is right that this doesn't take into account the fact that Smith's 2024 salary becomes fully guaranteed in February, before the start of the new league year in mid-March, and therefore before Seahawks can use the post-June 1 designation.
The whole "post-June-1" thing is pretty bizarre. I still really dislike the Broncos from the Seahawks' days in the AFC West, so I was loving that the Broncos would have to guarantee Wilson's $37M 2025 salary if he's still on their roster at the end of the fifth day of the league year, which will be St. Patrick's Day. I thought that meant they were going to have to eat the full $85M in dead money in 2024, which would have been devastating for them and delicious for me. But it turns out they can designate him as a post-June 1 cut but simultaneously have him considered not to be on their roster on March 17. Whut?!
Oh well, the $35.4M in dead 2024 cap and $49.6M in dead 2025 cap is pretty nice too. It just seems weird that he'll be in a "Schrödinger's overpaid QB" quantum superposition where he's both still on their roster until after June 1 and not on their roster on March 17.
