Won't happen.
If Joe keeps playing like he has do you really want to extend him beyond the two years?
Well, we wouldn't be extending him, since he's already under contract through 2021. So in short, yes. If he played like he did last year, I see no reason to move on from him. If fans actually took the time to look around the league (and specifically the College game) and look at the alternatives, it would scare people into loving Flacco. Its that bad. I mean you don't really think teams think that guys like Bradford and Osweiler are really good QBs do you? They just know what the alternative is. Or just pick any franchise that hasn't had a respectable QB in over a decade what they think. The old "o just go get somebody in the draft or FA mantra" doesn't seem to be quite so simple then...
I can only look at facts and one glaring change in the Ravens Record the last 8 years is that contract. Right or wrong its hampers the team from winning and neglects the other two phases of the game.