Sacks Have No Affect On A QBs Performance: A Statistical Correlation Between S/100 and a QB's Numbers

So I actually did some actual analysis. I've done posts in past showing you loyal viewers what seems to be a strong correlation between how many times a QB gets sacked per every 100 passing attempts and stats like YPA, TD/INT ratio, Completion Percentage, and Passer Rating. However, I actually did a scatter plot to determine what the exact correlation is between S/100 and these stats. First, I decided to study Brett Favre's career. I did this because I thought I would try to leave as many variables out as possible. Brett Favre is a great talent and he's had consistency throughout his entire career. He's also had a great sample size throughout his entire career which makes him, from a quantitative perspective, a great study. So if I wanted to study one individual player to help me with my study, I figured Favre was the best option. So here's data on how S/100 affected Favre's YPA, Comp%, TD/INT ratio, and Passer Rating:



Unfortunately, the correlation is essentially negligible between S/100 and all those stats. The R2 between S/100 and YPA is .002; between S/100 and Comp% is .0008; between S/100 and Passer Rating is .018; and between S/100 and TD/INT ratio is .018. Correlation is between -1 and +1 and is the correlation is 0, that means there is no correlation whatsoever. Very rarely will any number be exactly zero, but the closer the correlation equals zero, the less likely the correlation exists. These numbers are so small, that is laments terms, by looking at Favre's numbers, there is no correlation between S/100 and a QB's performance.

But then I did a quick analysis on Jay Cutler's short career and the numbers looked somewhat different.



Again, there is very little correlation between S/100 and YPA and Passer Rating; however, there is a very strong correlation between S/100 and Comp% and Passer Rating. The R2 for Comp% is very strong for Cutler, being .453 and for TD/INT ratio being .225. There is a strong correlation for Comp% and a slightly strong correlation for TD/INT ratio.

I figured then that maybe studying Favre solely isn't the best idea. Maybe my initial approach was wrong? I want to study the correlation for how S/100 affect ALL QBs, and by just studying one, maybe isn't the best. Maybe one individual QB isn't the best way to determine how often a QB gets sacked affects every other QB. Maybe one QB is better than another when getting sacked. So I decided to look at all QBs last year that had a minimum of 415 passing attempts to see how S/100 affects a QBs performance. This gave me 21 QBs ranging from the great Peyton Manning and Phillips Rivers to the crappy Kerry Collins and Marc Bulger. Here's what I found:



Again, I was disappointed. The R2 between S/100 and YPA is .125; between S/100 and Comp% is .049; between S/100 and Passer Rating is .162; and S/100 and TD/INT ratio is .172. The correlation is slightly stronger when analyzing all QBs as opposed to one, but the correlation is still fairly weak and essentially non-existent.

However, this research is not a total waste of time. Yes, overall, how often a QB gets sacked bears no relevance on how he performs. But that doesn't hold true on every individual QB. Some QBs, like Favre, it does not matter, and even on guys like Aaron Rodgers who gets sacked like crazy. However, on certain guys like Cutler, S/100 does not matter. And sometimes S/100 can show you how crappy certain guys are. Last year, Kerry Collins (min 415 attempts) had the 2nd least S/100, yet put up mediocre to awful numbers. So as a whole, S/100 shows no relevance, but on individual QBs, it may make a difference.