Quote Originally Posted by pbmax View Post
Thought about this again reading the preview article in OP. I think the bolded claim is wrong. Slopes at ANY points on the curve measure change in the same way and are not affected by the cumulative totals. So comparing Meredith/Staubach/Landry effect on the Cowboys to the Walsh/Montana/Young 49ers is indeed possible.

You could argue that different eras, with different rues affecting scoring make totals fluctuate, but that effect is strongly muted when considering point differentials rather than total points scored or allowed. The range may have increased over time as offense was favored, but the effect would not be as dramatic with the net figure.
Technically, the slopes on the left should be MORE impactful than on the right, as teams played fewer games 40-50 years ago than they do today so they had less opportunity to gain or lose point differential. +50 points over 10 or 12 games is far more impressive than +50 points over 16 games.

However, there is also the notion that football prior to 1970 was not nearly as competitive as it is today. There were a handful of teams that dominated an era...and then you had a bunch of mediocre teams that they routinely beat like a drum. That would make a slope at the right side more impressive.

So, as usual, statistics can be successfully argued either way. Let's just be happy with the fact that Green Bay's line is currently on top.