It is indeed difficult to compare FitzyClaus & Jim Kelly individually, because of their supporting casts on both sides of the ball. However, I'd be interested to know what the difference was, given the time they had the ball (a time-of-possession comparison). The bend-but-don't-break D of the Kelly years seemed to be on the field a lot, especially when the K-gun was in top form and scoring quickly. Of course, if FitzyClaus doesn't start piling up the wins, there's not a lot of point in comparing them.