So far, so good.
With his stellar performance this year, Titans running back Chris Johnson has proved that his prolific rookie campaign wasn't a fluke.
And chances are, he'll be a force for years to come, regardless of whether his team is winning or not (see: this year).
But just how many years is the question, given the historically volatile nature of his position.
Over the years, all have shown the signs.
From Franco Harris to Eric Dickerson; from Edgerrin James to Shawn Alexander, the age of thirty is kryptonite of sorts for running backs.
Holes become smaller as the once-quick first step wanes.
Plays that would have once been easy touchdowns get snuffed in the backfield.
Life is hard for star running backs in their thirties. Call it the James Dean position of the NFL. Their careers burn bright and fast, only to be over before it seems like they should be.
The odd thing is, the decline for a running back is usually sudden and swift. Gradual drop offs are rare.
We've seen it happen all too many times: the star back in his late twenties who gets the new, extravagant offseason contract...only to produce like a third stringer the rest of his career.
As a rule, 1,700 yard backs don't have a 1,100 yard "buffer" season before they fall into oblivion. It usually happens right away, and for a variety of reasons. But more on those later.
It's worth noting that there have been two exceptions to the rule in the modern era of the NFL.
Hall of Famer Walter Payton, of the Chicago Bears, enjoyed seasons of over 1,500 and 1,300 yards after his 30th birthday.
And most folks remember Curtis Martin in 2004, who, at 31 years of age, won the league rushing title with nearly 1,700 yards.
It could be argued that Barry Sanders would have produced well past that dubious milestone had he not retired early, ala Jim Brown.
But other than that, the going is tough for the position's "elder statesmen." Down the road, can Chris Johnson eventually join those two?
A speedster like Johnson doesn't take as much punishment as a traditional power back in the mold of, say, the Giants' Brandon Jacobs. That's the good news.
But regarding the bad news? Well, speed, his bread and butter, is only bestowed on the young. His style will need to evolve and expand in order for him to produce in his "geriatric" years.
And of course, there's the inevitable intangibles. He could blow out his knee and render all of the prognostication moot.
But if he stays injury free—and off of the cover of the Madden video games—he might have a shot at staying relevant.
In many ways, the Barry Sanders comparison is the most intriguing. True, their styles aren't carbon copies. But they're both alike in that they have a feast or famine way of running.
They either get you -2 yards or an 80-yard touchdown run. Also, they both avoid the big hits, as mentioned. Rarely do they grind it out in the trenches.
If Johnson enhances his elusiveness to compensate for the sure-to-come drop off in speed, then not only will the comparison be more accurate, but his career will obviously last longer.
Granted, there are many other outside factors. Coaching and scheme changes can sap the productivity from a back that's still in his prime.
Just ask Marcus Allen and Deuce McAllister. Thanks to Bo Jackson and Reggie Bush, respectively, their careers arguably never soared to the heights they could have, thanks to split work loads.
And on and on. There could literally be a full-length book written regarding the "what if's."
Time will tell whether or not Johnson can buck the trend and run wild into his thirties.
But so far, so good.