Like breaking up with a pretty nice girlfriend, I'm not sure if there's an easy way to say this, but the book on Blake Bortles has been written in the mind of NFL defensive coordinators -- play Cover 2 on third downs, on any money down, and in the red zone. He'll do the rest.
This is a basic Cover 2 shell defense.
NFL defenses usually figure out quarterbacks after a great season. (It's usually the second year but Blake didn't blow up until his second season.) It's the same struggle he's shown from games against the Carolina Panthers, Miami Dolphins, New York Jets, and Baltimore Ravens games last year... and every team we've played this year has run it with success. This isn't even emphasizing the dropped ints either.
Every single team we play this season will continue to run it until he shows he can beat it, specifically in the red zone. I'd be willing to bet at least 60% of his interceptions this season occurred against Cover 2, with the rest being on tips or dropped balls.
And before anyone says that sounds like a coaching issue -- yes and no. I mean, anyone who's ever played either high school quarterback (hell, or even Madden and NCAA) knows how to beat Cover 2.
The below red circles reflect the weaknesses against a cover two defense:
The disadvantages of the Cover 2 defense
The main weakness of the Cover 2 occurs in the middle of the field between the safeties. There are additional problem areas in between the corners and the safeties on each sideline, but these are dependent on the offense's route combination and ability to look off the underneath cornerback. An additional potential problem with the Cover 2 is that defensive pressure on the quarterback and against the run must also be provided nearly exclusively by the front linemen as all other defenders are involved in pass coverage. Even the middle linebacker is softer on run filling as he is responsible for a deeper drop into the soft area of that zone.
Knowing how to beat Cover 2 is one thing. Doing it in real life isn't as simple.
I am sure the coaching staff is telling and showing Bortles how to beat this coverage. But he's having to do it in real life, while:
1) not getting his receivers killed (all these knock out hits on our receivers in the middle of the field you've seen this season ring a bell?)
2) without throwing an interception
3) without forgetting to go through all of his mechanics, specifically footwork and looking off the corner. Both of these issues have an effect on the velocity or float of the ball.
He's failing in every one of these areas currently. He's struggling with the small windows.
TLDR: I don't believe that this is a new issue with Bortles. It's the same struggles he previously had. They have now been magnified because teams have figured it out and played more Cover 2 against him. And we can't force teams to abort the Cover 2, because we can't run the ball against soft 6/7 man boxes.
Note: The opinions expressed above are mine alone based on watching the film of each game this season at least twice, my experience reviewing tape, teaching coverages as a defensive backs coach, and my time played as a college cornerback. They are not representative of the entire Big Cat Country staff.