It's taken as a given that the Vikings' opponents played eight and nine in the box consistently, in order to slow down Adrian Peterson. Is that actually true, though? Mike Sando of ESPN's NFC West blog took a look at what the game charters at ESPN Stats & Information had to say. LINK.
Here's how defenders in the box are counted by ESPN:
ESPN charts box counts by looking at the "number of defenders at the snap who are within five yards of the line of scrimmage and no further than two yards outside the tackles or outermost player attached to the line" -- excluding defenders following skill players in motion unless those skill players come to a stop while the defender remains in the box. Defenders just outside the box area who are clearly rushing into the box are counted as in the box.
Sando limited the search to first and second downs. Against loaded boxes on those downs, Adrian Peterson gained 176 yards. That's good for sixth in the league last year. How does this compare to the rest of the league? Well, Minnesota faced loaded boxes on 12.7% of first and second downs. Surprisingly, this rate was just about league average; the Vikings were ranked 15th in stacked front percentage. Seattle led the league by facing 20.1%.
The numbers are from the season as a whole, so the early games while AD was still recovering are likely lowering the rate of loaded boxes. But given the Vikings frequent leads (and thus lessened need to pass) and the threat of Peterson, league average is quite shocking. Perhaps we shouldn't expect the Vikings to face fewer loaded fronts next year.Tip o' the hat to Football Outsiders.