Alex Smith won the 2011 NFC West Positive Impact Factor (what's this?). As you'll see below, it was a landslide victory.
Here's the 2011 NFC West Positive Impact Factor Standings (PIF with sacks counted as rushes like the NCAA in brackets):
1. Alex Smith, San Francisco 49ers, 45.4 (52.3)
2. John Skelton, Arizona Cardinals, 24.1 (30.6)
3. Tarvaris Jackson, Seattle Seahawks, 16.6 (32.9)
4. Kevin Kolb, Arizona Cardinals, -0.6 (26.9)
5. Sam Bradford, St. Louis Rams, -39.9 (16.7)
Alex Smith had his best PIF season as a pro in 2011. Smith bounced back from a 20.8 in 2010 to lead the 49ers to the playoffs for the first time since 2002. Smith had a 36.5 in 2009 as his previous best PIF.
John Skelton did not have enough touches to make the standings in 2010, but in his time on the field as a rookie, he produced a 18.1 PIF. His touchdown rate came up but his interception rate stayed pretty much the same.
Tarvaris Jackson's best PIF season was a 30.6 in 2007, which was also the only other season where he had enough touches to make the standings. His interception rate and touchdown production came down from that season but he lost fumbles at a higher rate in 2011.
Kevin Kolb didn't have enough touches to make the standings before 2011. This past season he was plagued by a high rate of fumbles lost. His interception rate was a touch high but not one that would kill his team.
After Sam Bradford put up a rookie PIF of 30.7 (higher than Peyton Manning's 22.1), I was very interested to see if Bradford would have a sophomore slump. Boy, did he ever. While improving on his interception rate, his fumbles lost rate went off the charts and his touchdown production fell by half.