As NFL scouting combine looms, is Mariota or Winston the better prospect?

Among the enduring reminders from the latest Super Bowl: Scouting quarterbacks is an imperfect science.

Seattle’s Russell Wilson was a third-round pick, and Tom Brady lingered until the sixth round before the New England Patriots grabbed him with the 199th pick. Meanwhile, you could fill two wings of the Hall of Fame with first-round flops.

And that brings us to this year’s NFL scouting combine, the six-day annual event that begins Wednesday and features the most highly touted pro prospects. They will be put through the paces at Lucas Oil Stadium by scouts, coaches and executives from the 32 teams.

Early projections — and they are fluid at this point — suggest there’s a strong possibility quarterbacks will be selected in the top two spots for just the second time in the past 16 drafts. In 2012, Indianapolis’ Andrew Luck and Washington’s Robert Griffin III went 1-2.

The top two quarterback candidates in this class are Florida State’s Jameis Winston and Oregon’s Marcus Mariota, Heisman Trophy winners who faced each other in this year’s Rose Bowl. Tampa Bay picks first in the draft, Tennessee is second, and both are in the market for a quarterback.

So which player is the better prospect? Depends on whom you ask, and that’s likely to be debated during the next two months of buildup to the draft (April 30-May 2 in Chicago).

Most of the questions swirling around Winston have to do with his character. He was accused of sexual assault (though never charged), received a civil citation for shoplifting crab legs, and was suspended for a game for standing on a table in his school’s student union and screaming vulgarities.

More of that type of behavior would be a huge headache for the NFL, which is coming off a terrible year of off-the-field transgressions by some of its stars.

“He’s tough, he gets smacked in the face, he delivers the football,” NFL Network draft analyst Mike Mayock said of Winston. “I think the bigger concern is whether or not this guy can be the face of your franchise. Let’s face it, he was the face of the Florida State franchise, and that didn’t stop him from making a bunch of bad decisions off the field.”

By all accounts, Mariota has impeccable character and leadership skills. The question about him concerns his ability to fit into an NFL offense, and whether his success in Oregon’s unconventional offense can translate to the pros.

“I think [Mariota] can make all the throws,” said retired quarterback Kurt Warner, a two-time NFL most valuable player who now works with prospects in addition to his work as an NFL Network analyst. “But due to the limitations of that offense, I didn’t see him have to make a lot of complex reads. I didn’t see him have to make a lot of contested throws. When he had contested throws, I thought he struggled a little bit more, especially with throws down the field.

“When the guys were open, he showed he had the arm strength and can do all of that stuff. But that’s my biggest question.”

Another quarterback to watch is UCLA’s Brett Hundley, who has shown an ability to make plays with his feet but still needs to prove he has the accuracy and pocket skills that teams want at the next level — at least to achieve his aim of being a first-round pick.

“I don’t think he can change what the negatives are about him by throwing 20 passes in shorts,” Mayock said of Hundley, who has his share of positives (he completed a career-best 69.1% of his passes last season) and negatives (he was sacked a combined 125 times in three seasons).

“My perspective is he should just show up and rip it. He ought to just let it go. The things that are hurting him in the evaluation process are anticipation, pocket awareness, things like that you can’t really show at the combine.”

Although much of the talk at the combine will concern quarterbacks, this is not regarded as a particularly deep class in that regard. There are lots of good running backs and receivers, a scarcity of safeties, and some highly talented defensive linemen — among them USC defensive end Leonard Williams, who is projected to be a top-five pick.

As for the challenge of identifying which college quarterbacks will thrive in the pros, Warner understands that better than most. After all, he was not drafted and went on to assemble a Canton-worthy career.

“The science part of it is, if you’re going to be the guy you were in college, you’re never going to excel at the NFL level,” he said. “The hard part of the science is, we don’t know how guys are going to develop and what their ceiling is.

“Tom Brady, he wasn’t a great quarterback coming out of college. But he hasn’t stopped growing, and I don’t know if we’ve seen his ceiling yet.”

A year ago, the quarterback at the center of the combine debates was Johnny Manziel, a first-round pick whose rookie season in Cleveland had far more downs than ups, and who entered a treatment facility (for unspecified reasons) early this month, according to an advisor to the player.

Sometimes, what looks like a high ceiling might really be a low floor.

Follow Sam Farmer on Twitter @LATimesfarmer