NASHVILLE, Tenn. -- If you’re not a special team blessed a with a Hall of Fame quarterback, the NFL ensures you can only be so good for so long.

It’s an ebb and flow operation, intended to create .500 teams over time. Forces work against you having sustained success.

For a very long stretch -- too long, I’ll now willingly admit -- that’s what I thought about the Tennessee Titans.

A team that isn’t entrenched as one of the best and isn’t a long-term bottom feeder should have good years and bad. Good stretches and bad stretches sort of offset each other, landing franchises around .500 over time.

Obviously teams want to hit that upper echelon and spend extended time there, to be the Patriots or Colts or Ravens or Packers. Teams have a lot more Super Bowl chances if they are always in the playoffs instead of visiting periodically.

Since they moved to Nashville and became the Titans, the franchise is 133-112.

Over the last month, I’ve found myself moving off grading them as a middle tier team heavily influenced by tides resulting from NFL gravity.

Their last playoff berth was in 2008, after which they are 29-40 (.420) with just one winning season (9-7).

That’s 69 games. Quite a long stretch. Tennessee’s record in that span is 24th in the NFL, not as good as Detroit, Miami, Arizona or Houston.

Those results have come through three coaches (albeit just five games from one), two general managers and at least a little work from eight different quarterbacks. Those results aren’t a downturn on an up-and-down curve.

They are a plunge. A nosedive. If you graphed it, there is little reason to plot the arrow as anything but a steep line pointing down.

That opens the door to a room with another level of questions.

They start with this: Do the Titans have genetic flaws and is there a procedure that can cure them?

I think they do have such makeup issues. There are too many areas that have remained problems for too long.

Roster-wise, it starts with three key positions: Quarterback, pass-rusher and receiver.

Quarterback is not an easy problem to solve, but the Titans spent the third pick on one in 2006 (Vince Young) and the eighth pick in 2011 (Jake Locker) without finding a long-term solution. Premium picks like those need to yield more than they got from either of those.

Maybe Zach Mettenberger is the rare sixth-round quarterback who pans out. He certainly has the size and skill set Ken Whisenhunt prefers.

But even a strong showing by Mettenberger in the second half of this season won’t guarantee the Titans don’t have to try again high in the draft.

Jurrell Casey is a quality interior pass-rusher, but the Titans haven’t developed a quality edge threat on defense since Kyle Vanden Bosch. KVB had an injury-plagued first three seasons in Arizona, then blossomed in Tennessee with 38.5 sacks in five seasons from 2005-09.

The last edge rusher drafted by the Titans to post a double-digit sack season was Jevon Kearse in 2002, who was their first-round pick in 1999.

Nineteen ninety-nine!

If Kendall Wright and Justin Hunter pan out, they’ll finally break a long-term whammy on wide receivers.

It’s a spot where the Titans failed with rare exceptions whether adding through the draft (Damian Williams, Kenny Britt, Tyrone Calico, Courtney Roby, Brandon Jones, et al) or free agency (Nate Washington has done good work to finally offset Yancey Thigpen and David Givens).

The cure at the root is better player acquisition.

Ruston Webster’s only responsible for the last three drafts. The holes in the roster where fourth- and fifth-year players should be pillars are the fault of the previous GM, Mike Reinfeldt.

Player development has been equally poor, and in time we’ll see if Whisenhunt and his staff can help more young guys emerge as legitimate contributors.

The Titans also have a long-standing personality problem.

Too often too much of the roster lacks killer instinct. They have often been overly content with having a chance to win a close game at the end rather than seeking chances to bury an opponent and doing it.

They have a long-standing habit of starting games slowly. They’ve been unable to forge an identity. They bring in players from winning situations, like Bernard Pollard and Delanie Walker, and the newcomers struggle to figure out what’s wrong or how they can contribute more to positive change.

Good teams win at home. The Titans are 15-19 at LP Field since 2010. Good teams win in their division. The Titans are 8-17 in the AFC South since 2010.

And it’s not just that they lose, it’s who they lose to. The Titans lost to the 2010 Broncos, the 2011 Colts, the 2012 Jaguars, the 2013 Texans and the 2013 Jaguars. None of those teams won more than four games. Take out their victories over Tennessee, and they were a collective 9-66 in those seasons.

And while the Titans fans try to withstand the poor play, they hear pledges about massive improvement of the game-day experience but are left to report that the team didn’t even have all the gates open on Sunday at LP Field to help people get inside for kickoff.

The game they ultimately watched was the worst collapse by a home team in NFL history.

It’s a mess, and it’ll take more than a surgical procedure, or a coaching overhaul, to fix it.

It’ll take some genetic engineering.

But the Titans can prevent themselves from becoming a perennial bottom third franchise.

Tommy Smith, who heads the new ownership group, has been in the post for less than a year and speaks constantly about not accepting the old status quo. He happily signed off on Webster’s selection of Whisenhunt, who is only five games into a five-year contract.

Smith and Whisenhunt are the start. They need to earn the faith of the fans.

The steering wheel may be turned, but it’ll be while before we see if the ship is actually turning.