Firstly, I think the answer has to be no for the Pats.
I think the offense has too many non-QB problems to become good next year even if all the high draft capital and free agency windfall are primarily applied to the offense. There are too many problems with both the OL and skill positions to make this an easy place for a QB to play.
And Mac has only been good when he was running a strong offense that minimized pressure on him and didn't force him off platform.
I believe that looking at his skills abstractly, Mac Jones can be quality starter.
Sure, his arm strength is below NFL average, but the top 2 QB's in the NFL this year by both DYAR and DVOA, Purdy and Tua, also have below average arms.
Mac also has better athleticism than most people give him credit for (not that he knows how to use it).
Accuracy is obviously a strength of his (NCAA record holder) and I believe he has shown at times that can be accurate on the run as well.
His pre-snap reads seem to be more than adequate (although post snap he often falls apart).
So why has he failed so miserably? I believe it's because he plays with a high base level of anxiety and can easily panic when anything goes wrong (as of course it often will for a below average offense in the NFL). And when he panics, he forgets all his fundamentals and makes both poor decisions and poor throws. That interception vs the Colts was one of the worst throws in Patriot history.
I also suspect that the painful injury Mac suffered in 2022 has added some physical cowardice to his heap of anxiety, and being labelled a dirty player likely has increased that by adding fear of retaliation. And as we saw with Tony Eason, an NFL QB can't be a coward and succeed.
While when Mac came out of college he has some superficial similarity to Brady, Mac has proven to be the anti-Brady: where Tom was as clutch as anyone in NFL history, Mac has been historically bad in high pressure situations or when the game is on the line.
I really doubt he can be coached up from that by anyone.
As we saw at Alabama, Mac benefits much more than most QB's when leading a superior offense. I think he would look much better at Miami or SF. And I think he will look impressive in anyone's training camp.
But the anxiety will always be lurking within him, and you can't trust him not to panic when pressured or when the game is on the line.
As a long shot, someone here once suggested that Zoloft or some other anti-anxiety/anti-depressant might actually help him calm down enough to play to his talent.
Zoloft and other SSRIs are apparently not banned in international competition by the WUDA ("World Anti-Doping Agency"). Does anyone know whether they are considered PED's by the NFL, and/or would trigger positively on NFL drug tests?
