We love the folks from Pro Football Focus and the advanced stats they put out there. Yesterday, they released their rankings of the NFL's offensive lines for the 2012 season, and not surprisingly, the Minnesota Vikings finished among the best in the league in that respect. Thanks to rookie Matt Kalil, the consistency of center John Sullivan, and stronger than expected play from Phil Loadholt, the Vikings offensive line was massively improved from just a season ago. At least. . .I thought it was. It turns out that the folks from PFF might have a slight disagreement with that. This year, they ranked the Vikings as the 9th-best offensive line in the NFL, with the following commentary: Stud: It might not be the coolest thing to say, but there's no denying that over the past two years the best center in the league has been John Sullivan (+27.3). Dud: The Vikings made a big mistake in keeping Brandon Fusco (-11.8) in the starting lineup when they had better options on the bench.