In the first part of this little series looking at how much the Titans offense improved when Vince Young came in, I wrote about how Collins' and Young's statistics compared to what we'd expect based on teams that normally change quarterbacks midseason. The findings on that weren't too surprising, namely that Vince Young played a lot better than Collins, pretty much across the board.
One of the reasons the Titans were able to turn things around, quite apart from the quarterback play, was that the defense started playing much better. Even excluding entirely the Patriots game, the defense allowed 27.8 points per game the first five games and only allowed one opponent the last 10 games to exceed that, when they gave up 42 to San Diego on Christmas. And, bad defenses don't only give up points, they tend to allow yards. While total yardage stats can be an unreliable indicator of team quality, defenses that consistently give up a lot of yards tend to leave their offenses in unfavorable situations.
A good example of this is the first Jaguars game. The Titans put up 379 yards, their 5th best total of the season, but only scored 17 points, because their best starting field position for the entire game was their own 23. Lousy returns played a role in this, in addition to the defense, but either way the offense was starting backed up and needing 50 or more yards just to get into reasonable field goal range. Since point production is thus a result of field position, I thought I'd look at how the two quarterbacks did with similar field position.