Pick Six - A Closer Look

Let me start by saying I am not a Lee or Jefferson supporter because I think it is way too early to make that judgement. What I would like to discuss is pick 6's because it is usually the first arguement when comparing the two quarterbacks.

First, what makes a quarterback likely to throw pick 6's? I know it sounds ignorant, but is it more a quality of the quarterback, or the presence of bad luck?
Another way to look at it... Are there 3 types of quarterbacks: One that does not throw interceptions, One that does, and One that throws pick 6's.
OR
Are there only two types: One that throws interceptions, and one that doesn't. The third category (pick 6's)a quarterback who throws interceptions but is UNLUCKY in the position of the defender, the defender himself(fast or slow), and other factors such as offense's willingness to pursue an interception.

The reason I raise this question is that I believe Lee's problems of throwing pick 6's can more easily be corrected than problems in mechanics, understanding the playbook, etc. If Lee is just a quaterback who throws interceptions but has had BAD LUCK in the past in that a good number of them were returned for touchdowns, then I think fans would be more willing to accept giving him another chance.

The bottom line is that if some of Lee's pick 6's could have been avoided by players tackling better after interceptions, etc. than he would look like a much better option. (please understand that I'm not trying to say that the interceptions were not his fault, but i'm saying maybe Lee's pick 6 problem isn't as bad as it sounds, and any quarterback who throws an interception has a chance to throw a pick 6's if there is a little bad luck or other factors involved.

Can someone with a deeper understanding please elaborate?