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?