Is it me, or do I sense that teams are going for it more often on 4th down this year? And maybe I'm imagining things, but I also get the feeling that teams have been even more daring since the Belichick 4th down decision against the Colts.
The three graphs below tell the story. The top two graphs depict the proportion of 4th down decisions by field position. The first graph is for the 2000-2008 seasons, and the second is for the 2009 season. The third graph isolates just the proportion of conversion attempts by field position so we can better compare the previous seasons with the current season.
As you can see, there is measurable increase in 4th down conversion attempts so far in 2009 compared to previous years. It's small--overall just 14.7% compared to 12.4%.
What about since the Patriots-Colts game? Since then, 4th down conversion attempts have increased from 14.1% to 16.0%.
So yes, teams are going for it more often, but not by much. It's probably too small of a difference to notice just by watching a sample of the games each weekend. But it is a start. The revolution is here--it's just moving in slow motion.