Pro Football Focus, the respected football analysis and analytics website, released on Friday its rankings of the top 101 players in the NFL from the 2015 season. Four Vikings players made the list, but not the man who was arguably their most valuable player last season.

No, running back Adrian Peterson, who led the league in rushing and was named a first-team All-Pro after helping to carry the Vikings and their conservative offense into the playoffs, was not on PFF's top 101 list.

And he was not even one of their 10 players who just missed the cut.

So what gives? Why did Doug Martin, Jonathan Stewart and Lamar Miller make their list but not Peterson, the NFL's leading rusher?

While PFF analyst Sam Monson conceded that Peterson "may still be the best pure runner in the league with the ball in his hands," he pointed to Peterson's fumbles in 2015, his lower frequency of broken tackles and his limitations in the passing game as reasons for his exclusion.

"His 2.3 yards per carry after contact was bettered by 28 other runners. Twenty-five other running backs broke tackles at a higher rate," Monson wrote in this explanatory piece. "And of course he is bad enough as a blocker and receiver that he effectively is only a two-down player that doesn't even see the field in the most critical situations for the Vikings."

While Pro Football Focus is probably the best website of its kind, which is why we decided to write about the curious omission of Peterson, it does have its skeptics, including Vikings head coach Mike Zimmer.

The Vikings, who relied on Peterson to be the centerpiece of their offense while winning the NFC North last season, obviously consider Peterson to still be one of the NFL's most valuable players. They officially decided in March to keep his $11 million guaranteed salary on the books.

Oh, and in case you are wondering, the four Vikings, in order, who made the list were outside linebacker Anthony Barr, safety Harrison Smith, center Joe Berger and nose tackle Linval Joseph. They all cracked PFF's top 50.