You know how I know that Chris Johnson, today and in recent seasons, is a risky fantasy football proposition?

Because arguments for CJ2K — or CJ?K, as he’s now known — have for years begun and ended with his expected massive volume of carries. It wasn’t his skill or efficiency or peripheral stats that sold fantasy owners on the merits of investing highly in Johnson, but his glut of opportunity.

I think this is well worth considering as we consider Johnson’s 2014 prospects as a member of the New York Jets, who signed the durable 28-year-old to join Chris Ivory in their backfield.

I’m guilty of this, as you know if you’re a faithful reader of this degenerate space. The Titans last summer were shaping up as one of the NFL’s run heaviest offenses, seemingly guaranteeing 300 totes for CJ?K. That made Johnson a seemingly safe, high-floor investment.

He finished with 279 carries, posted another abysmal yards per carry (3.9) and, quite amazingly, finished as fantasy’s No. 10 running back.

But there has been no legitimate fantasy case for Johnson beyond pure volume during his five-year run as a top-end running back. Almost all of his peripheral stats — the stuff that gives us clues as to what a guy is capable of in the right situation — are odious. To boot: Johnson forced a meager 21 tackles in all of 2013, making him less elusive than king plodders Rashard Mendenhall and Steven Jackson.

I could make a laundry list of numbers that prove CJ?K has posted RB1 (top-12) fantasy numbers thanks to massive opportunity and the inevitable 70-yard sprints to the end zone.

Johnson has averaged 4.5 yards per carry precisely once since his miraculous 2009 season.

Johnson averaged 1.84 yards after first contact in 2013. Only two running backs were worse.

Johnson averaged 2.02 yards after first contact in 2012. Only two running backs were worse.

Johnson averaged 2.11 yards after first contact in 2011. Only two running backs were worse.

40 running backs averaged more fantasy points per touch in 2013 than CJ?K.

53 running back averaged more fantasy points per touch in 2012 than CJ?K.

In short, Johnson is — and has been — a model of statistical inefficiency. Unless he seizes the starting gig in New York, I don’t see much of a reason to invest a high draft pick on the runner formerly known as CJ2K.

One year after somehow outperforming his draft position (he was drafted as the 12th runner off the board), Johnson is now the 24th running back being taken in way-too-early draft. Expect Johnson to sneak into the top-15 as spring turns into summer and more casual fantasy owners invest on name value alone.

Do I think CJ?K could justify a selection as one of the top-15 backs off of draft boards? Yes, of course.

If the question is whether Johnson will outperform his average draft position enough to be a draft day target, the answer is no, unless and until the Jets’ coaching staff anoints him the unquestioned starter and workhorse of a backfield in major flux. That seems unlikely.

Another potential anchor on CJ?K in 2014: The Jets’ offensive line, according to Pro Football Focus’ metrics, was the second worst in the NFL last season. There were only four offensive lines better than the Titans in 2013, blowing a big, gaping hole in Johnson’s claims that his blockers were to blame for his occasionally massive struggles.

Now the silver lining that could very well chip away your resolve to remain outside of the Chris Johnson fantasy business: the rotoViz similarity score app has CJ?K notching 13.9 fantasy points per game as a median projection in 2014, which would put him back in the top-12 runners. His low projection would make Johnson a top-24 option.

I think it’s too early to write off Johnson — or anyone, for that matter — as a must-avoid fantasy option for 2014. More than most runners, CJ?K’s draft day appeal will largely hinge on where he’s available in your respective leagues.

Just remember that CJ2K is long dead. Long live CJ?K.