This is a GIGANTIC thread.
I was playing Dreamcast with a fucking terrible Cowboys team in in the early 2000's that went 5-11 three straight years, and I still had a nice record. In hindsight, I used to be a beast.
Successful NFL coaches -- successes in any walk of life, actually -- all seem to be supremely confident, uniformly intelligent and diligently organized. Look at the cover of a recent Sports Illustrated magazine with Parcells, whistle around his neck, sporting a tough Vince Lombardi-like look.