This is a question that can only be answered by someone who has been personally embarrassed by "All-Day" Peterson.
The special thing about Peterson is his versatility. He has the ability to juke players out of their jock straps and lay out hard-hitting defenders with a simple lowering of his shoulder pads; see Al Harris.
He can outrun corners on his way to long TD's and at the same time hit linebackers out of their cleats. For many examples, just take a look back last year at what he did to a stout Chargers Defense.
He almost matched a future Hall of Fame runningback for yards last year in two less games, and we have to remember that this was a year after Tomlinson broke the NFL record for most rushing touchdowns in one season.
The expectations were so high after last year people started talking about AP not being himself and suffering a sophmore slump this year. What would a slump be for AP?
Right now, after the game against the Green Bay, he is on pace to rush for 1800 yards and thirteen touchdowns. That would be a career year for even the best running-backs in NFL history, and he does this with a guy named Gus Ferote attempting to relieve some pressure off of him. Teams may as well start putting nine players in the box.
He has put up over one hundred yards running in two thirds of his games this season and is averaging nearly five yards a carry. That is perhaps considered poor for this special back because he averaged 5.6 yards last year.
There are many things wrong with this Minnesota Vikings team that has underachieved this year, but number 28 is definitely not one of them. Peterson can single-handedly keep the Vikings in any game because every time he touches the ball you can expect a home-run. If Peterson can stay healthy, ten years from now Vikings fans may be celebrating as Peterson passes Emmit Smith for the all-time rushing leader in NFL history.
Nobody knows, but what we do know is that at least for this season "All-day" Adrian Peterson will be here all year to strike fear into opposing defenders.