Can Marcus Mariota succeed where recent Tennessee Titan quarterbacks have failed? Barring injury, this season might well answer that question. Many of the best quarterbacks asserted themselves during their third season.

-- Scott Boehm Via Ap

If Year 1 was a good start and Year 2 was another step in the right direction, what should we expect of Marcus Mariota in Year 3?

How about a playoff berth for the team he quarterbacks.

Granted, there are many other factors in play that will determine the success, failure or return to mediocrity of the Titans in 2017. Has the defensive backfield been successfully retooled? Can the offensive line remain one of the best in the NFL? Will the additions at wide receiver pay the expected dividends?

Yes, it’s a team sport broken down to offense, defense and special teams. But the team begins at quarterback. It is the X factor in a league where the rules are written in pursuit of parity.

So far, Mariota is right on schedule in his development, and that makes this an important season in his growth as an NFL quarterback. It isn’t uncommon for quarterbacks to make a significant jump in Year 3, particularly if they won the starting job as rookies.

Atlanta’s Matt Ryan came of age in 2010 with a 28/9 touchdowns-to-interception ratio. Oakland rewarded Derek Carr with a huge contract after he cut his interception total in half from his second pro season to his third.

As good as Andrew Luck was in Indianapolis in his first two years, he had a monster third season when he threw for 40 touchdowns.

Of course, it can go the other direction. Remember, Vince Young lost his starting job with the Titans in his third season.

As for Mariota, there’s plenty to like about his first two seasons. Sure, you’d prefer that he get rid of the ball on time (he’s been sacked 61 times in two years), but it’s hard to argue with 45 touchdown passes and 19 interceptions.

Note: He has not thrown an interception in the red zone (20-yard line and in) in his two seasons. And his 6.4-yard per carry average as a runner is a definite plus.

Right about here, I should note that I’m a big believer in Mariota. I think he can be an NFL star if he can avoid injury.

Granted, I had my doubts when the Titans made him the No. 2 overall pick in 2015. I was concerned that he might be a product of the Oregon offensive system and its scheme to matchups that were easy for the quarterback to exploit.

The first thing we worried about was whether he could master the routine snap from center. At Oregon, he lined up in the shotgun for virtually every play. In a pro offense, the quarterback is under center for at least half the snaps.

But I quickly became convinced he is the real deal after watching him closely in training camp during his rookie year. His athleticism was impossible to miss, but I also saw his ability to fit passes into tight windows.

Additionally, he took his craft seriously. He has an extraordinary work ethic.

Yes, the Titans have had hard workers at quarterback before. Nobody tried harder than Jake Locker, the team’s first-round draft pick in 2011.

But Locker had two issues that he simply couldn’t overcome: an inaccurate arm and an inclination to injury. That’s why he lost the starting job and ultimately stepped away from football after four pro seasons.

Going through the 2017 schedule, you can make the case that the Titans will have an advantage at quarterback in as many as 11 games this season. Assuming Luck is back and healthy, he gives the Colts the nod at quarterback in two games. The only other games in which the Titans don’t have the advantage are Oakland (Carr), Seattle (Russell Wilson) and Pittsburgh (Ben Roethlisberger).

Some will argue Baltimore’s Joe Flacco and Cincinnati’s Andy Dalton are better than Mariota – and there’s merit to that argument. Both have more impressive bodies of work coming into this season.

But if Mariota improves as expected in Year 3, I think it’s at least a wash in those quarterback-to-quarterback matchups.

As for the competition in the AFC South, it’s a mixed bag. Luck’s health remains a major concern in Indianapolis. With him, the Colts could be a playoff team. Without him, they’re toast.

From the Titans’ perspective, it’s best to assume Luck will be back when the teams play the first of their two games in Week 6. He’s a Titans killer, having never lost to Tennessee. But Jacksonville and Houston are different stories.

Jaguars quarterback Blake Bortles brings an 11-34 record as a starter into his fourth NFL season. He has a history of throwing the untimely interception. It’s possible the addition of Leonard Fournette at running back will take some of the pressure off Bortles. But it’s safe to say patience is wearing thin.

At Houston, most believe it’s just a matter of time before coach Bill O’Brien gives up on Tom Savage and hands the keys to rookie Deshaun Watson. If it’s Watson under center for the bulk of the snaps, there are bound to be growing pains.

All of which brings us back around to Mariota. You have to go back more than a decade to the glory days of Steve McNair to find a time when the Titans had an advantage over most of the competition at quarterback.

Prior to Mariota’s arrival in 2015, seven different quarterbacks had started games for the Titans after McNair’s exit following the 2005 season – Kerry Collins, Vince Young, Matt Hasselbeck, Jake Locker, Ryan Fitzpatrick, Charlie Whitehurst and Zach Mettenberger.

That’s quite a list. Lack of stability and production at quarterback is one of the reasons this franchise hasn’t been to the playoffs since 2008 and hasn’t won a postseason game since 2003. You can only go so far with lackluster quarterback play.

But that has changed. The Titans finally have a true franchise quarterback. For Marcus Mariota, Year 3 could be a season to remember.

Reach David Climer at [email protected] and on Twitter @DavidClimer.