How much did the Titans’ offense improve when VY came in? Part 1

Putting aside the issue of underperformance relative to expectations entering the season, the big story of the Titans’ 2010 season was going 8-2 to end the season after a disastrous 0-6 start.  There were multiple reasons the Titans improved, but perhaps the most important storyline reason for the improvement was the change at starting quarterback, with Vince Young replacing Kerry Collins.  The question I want to examine, since it’ll be of vital importance for the Titans in 2010 and going forward, is just how much the Titans’ offense improved when Vince Young became the starting quarterback, to what extent the improvement came in the passing game as opposed to the running game, and try to figure out whether or not the same level of performance can be reasonably expected in 2010.

The first question is what kind of change should we expect when a generic team has a midseason quarterback change?  Thankfully, we can get some idea of this from this post from the indispensable Pro-Football-Reference blog.  In looking at quarterback rate stats, we should expect Young and Collins to end up with roughly the same yards per attempt and completion percentage, but should not necessarily expect much commonality in terms of sack percentage, TD percentage, or interception percentage.  Now, what do we find?

Not quite what PFR’s analysis would have you expect, as a matter of fact.  Chart?

QB YPA Comp% TD% Int% Sack%
Collins 5.44 54.8% 2.54% 4.06% 2.96%
Young 7.40 59.8% 3.94% 2.36% 3.19%

*-QB statistical comparison based on statistics in games started only.

Isn’t that a lovely chart?  In every stat except sack rate, Vince Young’s performance was vastly superior to what Kerry Collins did.  And, the improvement in YPA isn’t just a result of the improvement in completion percentage.  VY averaged 12.36 yards per completion, compared to 9.92 yards per completion for Collins.  That means, in the two most important quarterback statistics, the Titans went from well below average with Collins to well above average with VY.

Note also that touchdown percentage-3.94% is more than 50% better than 2.54%, suggesting that, whatever else VY did, he was vastly more efficient in getting the Titans into the end zone.  Since red zone play was a forte of VY during his first stint as the Titans’ starter, this suggests that he retains the proverbial nose for the end zone.  And, of course, throwing 2 fewer interceptions despite 57 more attempts results in a much better interception rate.  On the downside, the sack rate is slightly higher-put another way, Collins was sacked every 34 dropbacks, while VY was sacked every 29 dropbacks; worse, but not significantly so in my estimation.

So, the first gloss on the subject is that VY performed much better than we would expect from a simple replacement of relatively equally-good quarterbacks.  We should be relatively confident in thinking this, because the statistical improvement is pretty much across the board, and large enough that it’s not just a small sample size or easily attributable to fluke.  But, alas, the application of greater context is necessary.  After all, VY attempted 57 more passes (254 as opposed to 197) despite starting 4 more games than Collins.  For the next post, I’ll try to put those 7 extra passes per start in greater context.