Yesterday, I discussed the average amount of yards lost on sacks over NFL history.  The average has been stable at around 6.5 since 1993, although it was much higher (for reasons still to be determined) in older periods.  Today, though, I want to look at the relationship between sack yards lost per sack and other variables for individual quarterbacks.

I looked at all quarterbacks with at least 224 pass attempts since 2002. The graph below shows those 522 quarterbacks and how they fared in both sack rate (X-Axis) and yards per sack lost (Y-Axis):

As you can see, there is not much of a correlation there (-0.10), although there is a slight relationship that as sack rate increases, sack yards lost per sack goes down.

What about running quarterbacks — do they have longer average yards lost due to sacks? Anecdotally, it feels like no: Michael Vick was at 5.9, Randall Cunningham 7.3, Cam Newton is at 7.6, Steve Young 5.7, Steve McNair 6.2, Donovan McNabb 6.4, Russell Wilson 6.4, and Tyrod Taylor is at 5.4.  What about over a larger sample?

Here is the same graph again, but instead of sack rate on the Y-Axis, I’ve plotted a measure of rushing prowess.  What measure? I used rushing yards per pass attempt, which should give some measure of running quarterbacks.  For example, last year, the top three players by that metric were Newton (1.53), Wilson (1.06), and Taylor (1.02). The top two years go to Vick — 2.81 in ’04, and 2.68 in ’06.

The correlation coefficient here is -0.20, indicating a weak negative relationship: as rushing prowess goes up, yards per sack lost goes down ever so slightly.

How about sack yards lost and completion percentage? Well, there is no correlation there at all.

What would you like to see in Part III?