Yeah, for cap purposes, it is (AFAIK) prorated bonus + salary. So, for example, you could have a 6 year contract with a 12 million signing bonus, with salary escalations from 2 to 4 to million in the first two years. That would give you a prorated cap hit of 2 mil + 2 mil for the first year and 2 mil + 4 mil for the second. (i'm not proposing that as an actual contract, just as an example)
I don't /think/ the guarantee matters except in cases where you want to cut the player before the contract has played out.
Is this close to correct?
I don't see how a cap-conscious team (like NE) could reasonably backload guaranteed money in a contract - the bonus proration (for cap purposes) prevents it unless you guarantee salaries, which are the opposite of how most teams operate except to frontload deals. As in Osweiler's case - the Texans upped the guaranteed money by guaranteeing his salary the first two years (when they're 100% certain they want him on the roster anyway) and if he's not the real deal after year 2 they can get out. If he is the real deal, he's in a good position of leverage to demand a new contract. That's a reasonable deal for both sides, really. He gets paid good up front, he's in a position to get paid again if he's good over the first two years, and the team has an out too.
But if you were trying to do it the opposite way - and I'm not positive you can, or maybe it's just never made sense for anyone to do, but my understanding is that the bonus is always fully guaranteed, and/or you can choose to guarantee
full salaries for certain years. In this case for cap purposes you want JG to be really cheap in 2018/2019, and only really start paying him in 2020 when you plan for him to start, then the construct of that deal would be dangerous in that you would have the 'signing bonus' guarantee, whatever that is would still be prorated at a lower number but then you'd be fully guaranteeing salaries 3-4-5 years down the line that could burn you.
Let's say he signed 5 yrs/$80m/$40m guaranteed...$15m being 'signing bonus'
(based on other deals QBs have signed this may be a tad high but I don't think this is totally unreasonable at $16m AAV, and certainly some QB-starved team, say Chicago, could easily offer 5/80/40 with a bigger up-front payday)
Year - Salary - Bonus
1 - $2m - $3m
2 - $3m - $3m
3 - $18m - $3m (salary fully guaranteed = cap $21m)
4 - $20m - $3m (salary fully guaranteed = cap $23m)
5 - $22m - $3m (no salary guarantee)
I mean, doable....sure? but if you're wrong about him you're ****ed. You can play with the numbers and up the signing bonus and lower some of the salaries, or pay him a little more 'salary' in the early years, but there's no avoidable risk in backloading any deal. And the only reason to do it would be to let Brady play it out "til he sucks", and why would JG want to wait that out if he believes he can be a starter somewhere now?
option 1 - trade JG this offseason, gives new team ability to buy in low money-wise and negotiate new deal with him of their own accord, continue to re-stock team to roll with Brady for the next 3-4 years before the Brisket is ready (best slow and low anyway), plus added benefit of no 'QB controversy' everytime Brady isn't perfect (though I suppose there'd be a "did NE do the right thing?" post here weekly)
option 2 - franchise JG after 2017 and try to trade him that way, realizing you may have lost some of your leverage/flexibility due to the tag salary, endure another year and a half of questions about when Tom Brady is done
option 3 - decide you believe JG is the next leader of the Patriots, deal with the ******** in the interim, force the GOAT out by cutting him 6/1/2018, eat the cap money, and move along (to say nothing of the century of bad luck this could usher in)
Presuming TB is still TB - and neither I nor anyone here or anywhere else has any reason to believe otherwise - option 1 makes the most sense to me. BB ain't gonna coach forever...regardless of that I don't think there is any point at which he would change his operational style and stop trying to build the future as well as the present, but there comes a time when a man has to think about his legacy. And Brady is still his best chance to win a few more Lombardi's before he hangs it up and can live long enough to watch them re-name the trophy after him.