Maxwellsdemon had a recent post about mobile QBs and how we define them.
He focused on the ratio of rushing attempts to passing attempts. I thought it would be interesting to look at two stats, QB sacks and QB hits (which have only been recorded for the past 5 seasons) to see what we can learn about QB mobility/escapability. The sack rate is sacks/passing attempts. The hit rate is QB hits/passing attempts. A QB hit is defined as a play when the QB gets hit while throwing or immediately after throwing the football. I "created" two new stats to analyze an offense's ability to keep their QB upright - the punishment rate (QB hit + sacks)/passing attempts, and the avoidance rate (Qb hits - sacks)/passing attempts. The punishment rate gives a pretty good indication of which QBs are taking a beating and which are not. The avoidance rate is interesting, but confusing and not as useful as the punishment rate. Make the jump with me and we'll take a look at league trends, team trends and some individual player insights.
First off let's look at the QB sack rate over the past five years for every team in the NFL. The average sack rate for the league for these 5 years is 6.5%. The leagues best passing teams are consistently below 4%. Being at or above 8% is bad.
Sack Rate (%) - sacks/total passing att
The sack rate has been decreasing every year for the past 5 years. In fact, 2010 was a great year to be a QB as you will see in the hit rate and the punishment rate numbers later. The Bears who gave up a league high 52 sacks in 2010 only gave up a sack on 10.5% of passing plays. By comparison 2006 saw 4 teams give up a sack on 10.5% or more of their passing plays.
The teams who have had the most effective passing attacks over the past 5 years (NE, NO, IND) all have really low sack rates. The one exception being the year that Cassel filled in for Brady. Brady, P. Manning and Brees are not the most mobile QB's but they don't get sacked for a number of reasons. They move well within the pocket to avoid the rush, they have good to great OLs and they all have quick releases. In terms of sack rate, the Broncos have been average except for 2008 when we tied the Saints for the lowest sack rate. Big Ben for the Steelers buys a lot of time with his legs and has a great 3rd down conversion rate because of it, but his scrambling leads to more sacks (and more hits as you'll see later). David Garrard of Jacksonville (starter since 2006) doesn't take that many sacks, but you'll see later that he takes a bunch of hits. Sacks can be a result of the a breakdown in protection or of a QB holding the ball too long. In general a QB who is more mobile (runs with the ball more) will take more sacks than one who is pocket passer (Vick vs Kolb, Young vs Collins, Garrard vs Leftwich), but sacks stats alone don't tell us the whole story. So let's look at hit rates over the same timeframe. Do more mobile QBs take fewer hits (when passing) than less mobile QBs?
The average QB hit rate for the NFL over the past five years was 12.9%. Teams with hit rates below 9% are good while 15% or above is bad.
QB Hit Rate (%) - QB hits/total passing att
From 2006-2009 the league average in hit rate was roughly 12%. In 2010 the league average "dipped" to 11.2%. This may have been a result of the new rules governing hits on the QB or it may have just been a good year for pass protection. QB hits are interesting to ponder because a good QB will often wait, as the pocket collapses around him, to make a throw resulting in him getting hit after (or during the release). Additionally a mobile QB like Big Ben, can escape the pocket and make a throw from outside of the pocket before he is hit. A QB with less "escapablity" would just end up getting sacked or throwing the ball away.
So while a good number is desirable here and some good passing offenses have hit rates below 9% (NO, IND, SD), there are some teams on here who have low hit rates who would not be considered good passing offenses (2006 SF, 08-10 TEN, 07 CLE). So it would seem that teams with strong running attacks can also have low QB hit rates because they tend to put their QBs in passing situations where they are going to be able to get the ball off without having to take a hit (shorter routes because of shorter yardage to 1st down). The 2008 Broncos had the lowest recorded hit rate at 3.4% in 2008. According to Advanced NFL Stats, Cutler only took 21 QB hits in 16 games in 2008 (only 12 sacks, too).
So let's look specifically at some of the individual QBs who are considered mobile and see how they fare in terms of hit rate: Vick, Garrard, Cutler and Young. Vick started 16 games for the Falcons in 06 and 11 for the Eagles in 2010. Garrard started 68 of the Jags 80 games during this time frame. Cutler made every start but one for his teams from 07-10. Young started 28 of 32 games for the TItans in 06 and 07. The ATL hit rate for 06 is on the high end, the PHL hit rate for 10 is about average (Kolb made 5 starts). The JAX hit rate for the entire time period is very high - bottom quartile of the league. The Broncos with Cutler starting (07 and 08) were average and great at hit rate, while the Bears in 09 and 10 were average and slightly below average (higher hit rate). The Broncos hit rate in 09 and 10, with the relatively immobile Orton starting, was actually lower than in 07 (and the 2010 Broncos OL was poor for the first half of the season). TEN in 06 and 07 was average, but in 08 with the relatively immobile Kerry Collins starting 15 games, they were second best in the league. Bottom line is that QB mobility does not lead to fewer QB hits.
Time for some punishment
If you add QB hits and sacks then divide by total passing attempts, you get what I am calling the QB punishment rate. Note - this doesn't take into account the punishment a QB receives on a hit while running the ball. While it is possible to have a winning team with a QB who takes a lot of punishment, most teams with winning records allowed their QB to take less punishment than average (correlation of -0.43 between punishment rate and winning %, i.e. lower punishment rate means more wins). Only 15% of the time did a team who was in the bottom quartile in punishment rate have a winning record (24 instances in 5 years with PIT and BAL combining for 7 of those). The average punishment rate over these five years with 18.4%. The best teams are below 14% the worst are above 25%. Take a look at the stats
QB Punishment rate (%)
So it should come as no surprise that the best teams here are the best passing teams in the league - IND and NO are consistently at the top of the league in keeping their QB upright. There were some surprises here though - TEN and ATL have both been superb at keeping their QB upright for the past three years. TEN has been ranked 28th, 23rd and 25th in passing (based on yds) during those years. ATL was ranked 14th, 14th and 15th in passing yds. Here's the commonality - both teams ran the ball very effectively in those three years. So the conclusion there is that it's easier to keep your QB upright if you can effectively move the ball on the ground (well duh!), but one does not necessarily lead to the other. The Jaguars in 09 were in the top third of league in rushing (10th), but second to last last in punishment rate - getting their QB hit or sacked on 30% of their passing attempts. David Garrard is considered a mobile QB. The 06 Falcons lead the league in yards rushing, yet they were one of the worst teams in terms of QB punishment rate (25.2%). Michael Vick was the Falcons QB in 06; he is the poster child for QB mobility. The Broncos have been average to slightly better than average in QB punishment over the past 5 years with the exception of 08 when we were the best in the league.
On the bad end of the spectrum, the Bills, Raider, Lions and Jags have all done a really bad job of keeping their QBs upright. The 09 Bills (who started two rookie offensive linemen) have the dubious distinction of having the highest single season punishment rate at 33.3%. Three different QBs started for the Bills that year (Edwards, Fitzpatrick and Brohm) and all of them were getting the snot knocked out of them on every third dropback. The 06 Raiders were almost as bad at 32.3% based largely on the highest sack rate during this time frame (14.7%). Big changes in the punishment rate from year to year for a team could usually be attributed to a change in starting QB or a dramatic shake-up (injuries, rookies starters) on the OL.
I am not going to discuss the avoidance rate much, because I found the analysis more confusing than useful. Very few teams had a large difference between the hit rate and the sack rate. Some were very good passing teams (08 Cardinals, 08-10 Colts) while others were decidedly mediocre or bad passing teams (08 Bucs, 09 Bills). Teams with a small difference were plentiful making it hard to determine what a really meant to have a small difference between the number of QB hits and sacks. The QB hits stat has only been recorded for the past 5 seasons, but no team has had fewer QB hits than sacks. The closest were the 06 Rams (57 hits and 52 sacks) and the 10 Faiders (43 hits and 37 sacks).
1. Having a mobile QB will not lead to fewer sacks
2. Having a mobile QB will not lead to fewer QB hits, and generally leads to more QB hits
3. Teams with high QB punishment rates rarely have winning records
4. Having a good running game does not mean your QB will take less punishment
What does these mean for the Broncos specifically in 2011?
Starting TT over KO will not lead to fewer sacks or fewer QB hits. Behind the same OL, the data says that TT will take more hits than KO (but not necessarily more sacks). If the Broncos want to finish with a winning record for the first time since 2006, they should make sure that whoever starts at QB takes as little punishment as possible (well, DUH!).
So there you go. You've wasted another 20 minutes of your life reading a football blog with a bunch of numbers on it. Hopefully you've gotten something out of reading this. I know I gained some insight by putting it together.