I defined "best" as which qb gives a team the best chance to win.
Well see that would depend on the team he is on , the coaches, and what kind of offense will they run.
A good example is lamar jackson , he had a great year, because harbaugh designed the offense to specifically fit his skill set.
many qb's are forced into a specific offense, not designed for them, and that often does not work out good.
To me you need to look at the whole offense, and the qb skill set and design the offense around what you have, but most teams
dont do that.
Sometimes teams with a good passing qb, will wind up throwing the ball way too much, like NO, and they do good, but not so much in playoffs.
JG did that with romo, throwing 40 to 50 times a game, and that is too much. The game where orton played and lost JG had him throwing
45 times, which was too much , all the while ignoring the run game which at the time was fairly good.
So rating qb's is flawed , because there are too many variables.
As a pure passer, dak is a little above avg, and while he could run good and more often he doesnt. And I dont mean designed runs,
I mean drop back to pass, and if a lane opens up take it.
If u put lamar with JG, he would not do as well as with harbaugh, and JG now has a qb that is a better fit for what he likes to do which is pass a lot.
And jones is a good passer if they can give him a decent pocket and time.