I friend sent me a note analyzing data on NFL quarterbacks past and present, and came up with this top five based on a points system that ranked the top 40 all time quarterbacks on a number of dimensions, such that the lowest score is the best:
1. Joe Montana - 54 Points
1. Tom Brady - 54 Points
3. John Elway - 68 Points
4. Terry Bradshaw - 84 Points
5. Peyton Manning - 86 Points
Even without going through the numbers, I can live with this. The conundrum is that Peyton feels to many, including me, like he may be the greatest of all time, but nearly any numerical or scientific analysis puts him behind other quarterbacks, including Tom Brady. So why do our hearts tell us something else? I have two hypotheses:
- He is the most interesting guy in the history of the NFL before the ball is snapped. This is a criteria I never would have thought even existed 10 years ago. But Peyton has made watching the team at the line of scrimmage before the play starts totally compelling. No one in history is even close. Think of all the great quarterbacks in history -- you think of them throwing, right? With Montana, for example, I see those slants to Jerry Rice, hitting him in stride. Now, how do you picture Peyton? Yelling Omaha at the line of scrimmage.
- He is money in advertisements and live appearances (e.g. Saturnday Night Live). Have you seen Joe Montana's and Farvre's ads? Stiff. How much better would Peyton have been in There's Something About Mary? Only Bradshaw is close.
Peyton gets dinged for being a poor bad-weather quarterback. I am not sure if the numbers support this hypothesis, but he would have to go a long way to being worse than Aikman was. I was in Dallas during their three Aikman-era superbowls (actually I lived in Denver for their 2, and St Louis for theirs, and Arizona for theirs, all of which is payback for growing up an Oiler fan). Aikman always disappointed in bad weather. The one year of their four year run in the 90's that they did not go to the Superbowl, they lost to SF in the Conference championships. That day, the moment I saw it was raining, I knew the Cowboys were doomed.
One of the classic mistakes in graphics is the height / volume fail. This is how it works: the length of an object is used to portray some sort of relative metric. But in the quest to make the graphic prettier, the object is turned into a 2D, or worse, 3D object. This means that for a linear dimension where one object is 2x as long as another, its area is actually 4x the other and its volume is 8x. The eye tends to notice the area or volume, so that the difference is exaggerated.
This NY Times graph is a great example of this fail (via here)
The Tebow character is, by the data, supposed to be about 1.7x the Brady character. And this may be true of the heights, but visually it looks something like 4x larger because the eye is processing something in between area and volume, distorting one's impression of the data. The problem is made worse by the fact that the characters are arrayed over a 3D plane. Is there perspective at work? Is Rodgers smaller than Peyton Manning because his figure is at the back, or because of the data? The Vick figure, by the data, should be smaller than the Rodgers figure but due to tricks of perspective, it looks larger to me.
This and much more is explained in this Edward Tufte book, the Visual Display of Quantitative Information. You will find this book on a surprising number of geek shelves (next to a tattered copy of Goedel-Escher-Bach) but it is virtually unknown in the general populace. Every USA Today graphics maker should be forced to read it.