Chris Johnson can be fast, and elusive, and shifty, and all the things that make an elite (*cringes*) running back elite. But he can also dance, and plod, and entirely miss running lanes. Too often over the past two seasons he’s either been one of those two things, or nothing. There’s no even ground with Johnson, and no average performance. There’s a boom, or there’s a bust.

That’s why while the sex appeal of the high end of Johnson’s talents is understandably irresistible, the low end makes a long-term financial commitment difficult. Combine that inconsistency with his inherently risky status as a running back, and we arrive at one of the most perplexing players when it’s time for a general manager to either give Johnson a contract, re-structure his current one, or manage the player financially in any way.

This week the Titans had a choice: commit to their polarizing running back at a heavy expense for 2013, or jettison him and start over. They’re reportedly set to make the only logical decision available to them with their still young and still developing quarterback in need of support. But that doesn’t make it any less painful.

Earlier this afternoon Jason La Canfora reported that Tennessee will exercise Johnson’s contract option for 2013, which is triggered five days after the Super Bowl. It’s worth $10 million, $9 million of which is guaranteed, which is pretty heavy cheddar for a 27-year-old RB.

The problem with Johnson primarily lies in his inability to separate with any consistency. Often this past season he lacked the space to initiate that extra gear, as he had only eight runs of 20 yards or more, which is a massive tumble from his 2009 record-setting year when he had 22 such chunk plays. There was an uptick in his production between weeks six and 10, when he rushed for 561 yards at a pace of 112.2 yards per game. But therein lies the roller coaster, and its inevitable diving.

That hot stretch followed an opening to the season when Johnson had 30 or fewer yards in four of the Titans’ first five games. And then although he closed out the season much better, there was still a mediocre stench to Johnson’s plodding when he recorded a similar streak of woe (less than 60 yards in four of Tennessee’s final five games). Overall there were also six games when he averaged less than three yards per carry.

In reality, that sucks, and for the needs of my many fantasy fiend friends, that sucks too. For some perspective to show how much Johnson spiraled throughout this season, he averaged 10.1 fantasy points per game, which is only barely ahead of Reggie Bush (9.9), and — big gulp — Shonn Greene (9.7). Johnson will still likely be a second-round pick at worst in most leagues next August due to his boom potential, but make that pick while bracing for the upcoming pain of his inconsistency.

If we’re still having this conversation a year from now, that fantasy stock will fall much further as the intolerance among potential owners grows, and for the Titans, the urge to move on and rid themselves of a bad contract and an underachieving player will reach a breaking point. To avoid that fateful day and to maximize Johnson’s potential, upgrading the offensive line needs to be a top priority. Now.

Back in late September during the height of Johnson’s early-season struggles I looked at some pretty depressing digits. At the time, he had 21 rushing yards over two games, at an average of 1.1 yards per carry. No, seriously.

Why was this insult to rushing happening? He was pretty much being hit directly after the handoff. Every handoff:

In a stat dug up by ESPN Stats and Information and mentioned Thursday by Matthew Berry on his daily fantasy podcast, Johnson has more yards after contact than he does before contact. Again, overall he has 21 yards, but after contact he’s rushed for 23 yards. Wait, what?

Yep, he has more yards after contact than he does total positive yards because he’s facing initial contact in the backfield so often. In fairness, some of that could still be on Johnson, and his inability to just choose a damn hole. But what if there is no hole, ever? A circumstance in which a runner’s yards per carry after contact (1.2) is more than his overall yards per carry (1.1) says this is a problem which goes far beyond his control.

Tennessee’s O-line play improved eventually, and then it reverted back to sucking late in the season. Consistency there will lead to more consistency from Johnson, and more smiling by both Titans fans, and his fantasy owners.