Adrian Peterson isn't backing down from the 2,500-yard prediction. It's probably too late now anyways. He's been asked about it so often that to back away from it now would be un-Adrian.

Heck, he even added a 20-touchdown forecast for the season in a sideline interview with Ben Leber during the Vikings' preseason finale last week. So 2,500 rushing yards and 20 touchdowns… that would be a pretty good encore for the NFL MVP, huh?
The 20 rushing touchdowns wouldn't be a record. It's been done 11 times before. Peterson's career best is 18 back in 2009 so it would represent a personal best for him. So there is that.
The 2,500 yards, of course, is a different matter.
Even the most casual football fan knows that Peterson fell nine yards short of breaking the single-season rushing record last year, finishing with 2,097 -- compared to the 2,105 that Eric Dickerson totaled in 1984.
Therefore, I thought it might be kind of interesting to put 2,500 rushing yards in a little perspective as compared to the other NFL counting stats records.
To obliterate 2,105 by 395 yards would be an 18.8 percent increase. Full disclosure: I used this online percentage increase calculator to double-check my math because I didn't trust my own arithmetic. It's pretty handy. Try it.
You can't top the single-season rushing touchdown record of 28 (set by LaDainian Tomlinson in 2006) by 18.8 percent because you can't score partial touchdowns. Scoring 33 would be a 17.8 percent increase, which is close enough. That would be impressive, but going from 28 to 33 doesn't really sound like much. It doesn't sound as awesome as going from 2,105 to 2,500.
We need bigger numbers and bigger stats to compare.
Instead, let's look at the single-season marks for receiving yards and passing yards.
You may remember that Calvin Johnson broke the record for receiving yards in a season just last year. I know the Vikings remember since they have to figure out a way to contain him in the season-opener on Sunday. Johnson recorded 1,964 yards receiving, breaking the old record of 1,848 by Jerry Rice. That was a "paltry" 6.3 percent increase. If Megatron or someone else wants to break the record of 1,964 receiving yards by 18.8 percent, they'd need a ridiculous 2,333 yards.
Drew Brees set the record for most passing yards in a season with 5,476 in 2011. For a quarterback to top that many passing yards by 18.8 percent he would need to throw for a whopping 6,505 yards. Absurd. Some might say impossible.
So that's the kind of record-smashing performance Adrian is shooting for this season. Think about that while you watch him sprinting down the sideline. Think about that while Paul Allen is screaming "And he's loose!" as Peterson busts into the open field. Just think about that.
A lot of NFL observers have thought about it. Few think it's possible. I'm one of those few.
Coming back from ACL surgery as fast as he did was thought impossible. Coming back from ACL surgery and actually being better than he was before the surgery had to be impossible. But Peterson made it possible.
I'm done doubting Adrian. If he says he's running for 2,500 yards, who are we to doubt him? He's earned the benefit of the non-doubt. This isn't a homer thing; if Calvin Johnson says he's shooting for 2,333 receiving yards, I'll probably believe in him too.
My calculator also tells me that in order to rush for that many yards in a season he will need to average 156.25 yards per game. In his last 10 games last season he averaged 159.8 yards per game.
The countdown to 2,500 yards starts Sunday.
Bo Mitchell is the Vice President of Content at SportsData
You can follow Bo on Twitter at @Bo_Mitchell