Fact 1 - Bortles has consistently been a bad QB in the NFL
Fact 2 - Mannion hasn't gotten to play yet in the NFL
Take those 2 facts and you get that it is a very low probability for somebody who has been bad for so many games to all of a sudden become a much better player. Of course, the wildcard is McVay, so I give is some chance. However, since Mannion hasn't really played, we have never seen what he can do with game planning and getting all the reps and playing with starting players. So since he has no track record, maybe he will surprise, i.e. Kurt Warner, Trent Green, Marc Bulger.
On the other side of it. While Bortles has been bad, he still has played many downs in the NFL and has an idea on what he is doing. Mannion could be completely in over his head and have a Sean Covington performance where he completely gets destroyed because the moment is too big.
So While I think the more likely outcome is that it will be a big blowup for both QBs. Mannion will likely do worst. Still, I think there is a better chance of Mannion doing really good than Bortles because it is still an unknown since he never got a chance. Bortles, unless McVay is truly a miracle worker, is going to be a bad QB. 80 QB rating career is bad in my book in the modern day NFL.
