Marcus Mariota dives for the pylon during Sunday’s loss at San Diego. The second-year QB accounted for four touchdowns but had a fumble and interception returned by the Chargers for touchdowns.

-- Ap Photo/Rick Scuteri

So exactly what do the Tennessee Titans have in Marcus Mariota? Mariota’s performance in Sunday’s 43-35 loss to the San Diego Chargers was in some ways a microcosm of his efforts to date with the Titans.

There were plenty of good things – very good things – accomplished by Mariota and the Titans offense. Three touchdown passes, another touchdown on a 14-yard scramble and a total of five touchdown drives.

Then, of course, there was the down side – three more turnovers. Mariota lost his fourth fumble of the season and had two more passes picked off, giving him eight interceptions on the year.

To make matters worse, the fumble and one of the interceptions were both taken back for touchdowns – the fifth time this season that an opposing defense has scored directly from a Mariota miscue.

To his credit, Mariota stays even-keeled, even though the mistakes have to be gnawing at him, given the type of competitor he is.

“Obviously, I can’t fumble. That’s going to put us in bad situations,” Mariota explains. “On the final interception, I probably should have just moved on in my read.

“Kendall (Wright) did a good job winning, if I would have laid the ball out there a little more to the outside, it’s a completion.”

Titans coach Mike Mularkey also weighed in.

“Look, he’s 23. He just turned 23. I think he’s started 21 games now. He’s doing OK in a lot of areas,” Mularkey explains. “That’s one area that he needs to do better in. I mean, if there’s one area – obviously, it’s a critical area and it’s been an issue for us in these losses – but he does a lot of really good things, and I’m glad he’s our quarterback.

“There’s no question about it. At the end of the day, I’m glad he’s our guy behind center.”

Mularkey has a valid point, especially when you sort through the numbers of 21 starts and make the comparison to another young quarterback at that juncture, who is currently the talk of the NFL.

While numbers don’t tell the whole story, they are a good indicator of Mariota’s success at this stage of his career and potentially project where he might be in the near future.

Consider this: Oakland’s Derek Carr is one of the hottest quarterbacks in the league, having led the Raiders to a 7-2 record this year in just his third season in the NFL. There is even talk that Carr should be the MVP of the league, given the outstanding season he has had to this point in the season.

But through his first 21 starts, Carr was on a very similar track to Mariota. In fact, his statistics were not as good in many categories.

In that span, Carr completed 451 of 761 passes for 4,441 yards. The Oakland QB also threw 29 touchdown passes and 15 interceptions.

During those 21 starts, the Raiders, who were in the midst of what now looks like a completed rebuild, were a not-so-glorious 5-16.

Now, the numbers for Mariota through 21 starts: He has completed 414 of 661 passes, good for 5,005 yards, with 36 touchdown passes and 18 interceptions. His won-loss record is 7-14.

So while the growing pains are still excruciating – as the Titans found out again on Sunday – Mariota’s overall path seems to be going in the right direction.

Terry McCormick covers the Titans for TitanInsider.com