We're going to have to agree to disagree, however, I do agree that the SI article didn't employ proper statistical analysis.
I don't really understand the disconnect you are having here. The first article on Drew Brees linked above talks about just Drew Brees. It doesn't attempt to make any kind of general statement/proposition to apply to all QBs, or to all QBs who meet a specific criteria. That's the difference. Why is this hard to understand?
You're completely missing the point and I'm not the one that's keeping this subject alive--I said we'll have to agree to disagree. SI put together a single sample of data that they arbitrarily determined, crunched it and offered a projection. Chase put together a single sample of data using criteria that he arbitrarily determined, crunched it and offered a projection. He's using more mechanics, but he's doing the same thing that SI did. He's arguing that SI should use one set of data, come up with a hypothesis and test that hypothesis on a second set of data. OK, fine, I'd like to see that too, but why is he criticizing SI's study as only "useful in retrospect" when he's also coming to a conclusion using only a single set of data. The point here is that if you use a single set of historical data to come to a conclusion, that conclusion is only applicable to that set of data whether you use more rigorous mathematical mechanics or whether you're coming up for a rule to grade QBs or a floor/likely performance for a QB. Again, I'm not criticizing FBGs, its the nature of football and the limited sample sizes we have to work with. FBGs handles it their way, Football Outsiders attempts to overcome that by DVOA/DYAR metrics that look at individual plays, etc. We all live with it.