You ever take two bottles of 5-hour Energy in the same day?

After one bottle, you feel energized and alive. You clean the whole house, you paint the garage, and you write the first chapter of your novel. But for some reason, the second bottle never works the same.

Each bottle has exactly the same ingredients, and you are the exact same person, but the surge from the second bottle never matches the bug-eyed rush you get from the first.

Rushing seasons in the NFL are like that. To have a truly great season, everything has to go exactly right. The running back AND each of the five offensive linemen need to ALL stay completely healthy for ALL 16 games. Adrian Peterson had a year like that last year.

In order to get a feel for what we can project AP's numbers to be this year, I looked at the previous Top 25 rushing totals of all-time, and I compared them to the totals for the same running back for his next season. The results from the "follow-up" year, generally resemble the results of that second bottle of 5-hour Energy: They're a letdown.

In the year following a Top 25 rushing season, there was a 20% average drop-off in production. The average yards per game dropped from 120 to 95. (I calculated this is on a per game basis, so injuries wouldn't affect the count. If you don't account for injuries, there was a 35% drop-off!)

Essentially, if a back doesn't get injured, you can expect him to put up about 80% of the production from his previous "all-time great" year. For Adrian Peterson, that would mean 1,678 yards.

*Note: The sharps in Las Vegas have AP's expected rushing total at 1,750 yards. Considering this is higher than the "historical expected total" if he were to stay healthy, and doesn't take into account any likelihood of injury, I'd say betting the "under" on this total would be fairly wise. (If I was a betting man)

*Note: Larry Johnson had TWO of these Top 25 all-time rushing seasons. Hmmm.

*Note: Eric Dickerson led all others with three of these seasons.

*Note: Six players had at least two of these seasons each. Which means there is a fairly high chance of having a second great year at some point (even if it's unlikely to be the next season). This bodes well for Chris Johnson, who currently has one of these seasons, and is still in his prime.

*Note: Only three times, did someone on this list outperform themselves the next season, and all three of these totals were the low-end of the spectrum. (Between the 20th to 25th best seasons: Eric Dickerson, Terrell Davis, Larry Johnson.

Notes About the Calculation of Stats:

•I used the Top 25 seasons of All-Time prior to AP's 2012 season, otherwise, there would have only been 24 samples.

•I left Marcus Allen's follow-up year out of the averages because the Raiders brought in Bo Jackson that season, and I just don't see that instance being relevant moving forward.

•There were only slight changes to the overall numbers if the calculations were for Top 10 rushing seasons of all-time, I therefore didn't mention them in the interest of brevity.

Check out our in-depth analysis on all fantasy running backs here.