E[earned runs] = ERA. var[earned runs] = ?

Kids Prefer Cheese | Angus | mean-variance domination

Kevin Durant has repealed the laws of finance and CBS sports can prove it!

There's supposed to be a trade off between average return and variance where you get a higher return by bearing more risk. Yet, of all the leading scorers in the NBA (and he is THE leading scorer) Durant has the lowest variance of points per game.

Here's the picture (click the pic for a more glorious image):

I've been wondering for a while why variance is almost never reported as a sports statistic. Wouldn't it be helpful to know the standard deviation of a QB's rating?

It's not like sports analysts are numbers shy, or reluctant to invent to measurements.