Aaron Rodgers won the 2011 NFC North Positive Impact Factor (what's this?) standings by a landslide. That's not really surprising given the number he put up was outstanding.
Here's the 2011 NFC North Positive Impact Factor Standings (PIF with sacks counted as rushes like the NCAA in brackets):
1. Aaron Rodgers, Green Bay Packers, 65.6 (67.2)
2. Matt Stafford, Detroit Lions, 42.4 (49.8)
3. Christian Ponder, Minnesota Vikings, 17.3 (28.9)
4. Jay Cutler, Chicago Bears, 11.5 (33.1)
Rodgers has improved his PIF each season in the NFL as a starter. His lowest rank in the NFL as a starter has been 9th in his first year as a starter (2008). He had a PIF of 41 that season.
Stafford has come a long way since his PIF of 19.7 in 2009. His touchdown production rate is up while his interception rate has come down a lot. As long as he stays healthy and plays like he did this season, the Lions could consistently compete for a playoff spot.
Ponder, the rookie out of Florida State, didn't have a terrible year as a rookie. His touchdown production rate wasn't bad at all actually but his rate of turnovers will need to come down if he is going to make it as a starter.
Cutler slipped a little from his PIF of 13.9 in 2010 and fell way down from his PIF of 44.6 in 2008 (5th in the NFL). His touchdown production has remained about the same throughout his career. What has changed the past two seasons is his lost fumbles. The last two seasons, he has fumbled 17 times and lost 9 of them. He's always had a problem handling the ball, but only lost 9 fumbles from 2006-2009.