Quote Originally Posted by Harlan Huckleby View Post
I'm afraid those graphs have got me very cranky indeed. I'm all for integration, but this is ridiculous. It is NOT useful for looking at eras. Slopes at left end of plot are less significant than changes at right. A more interesting graph would just show margin of victory, with maybe a smoothing filter (moving average) to show era trends clearer.

Very disturbing. I'm inconsolable - don't talk to me about this again.
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.