Here's why QB Marcus Mariota faces uphill battle against a draft slide

INDIANAPOLIS – Marcus Mariota hasn't studied Colin Kaepernick's game. He hasn't broken down film on Robert Griffin III, either. And Johnny Manziel, well, nobody asked, but it's a sure bet the Oregon Ducks star quarterback hasn't spent much time on Johnny Football.

As Mariota put it Thursday at the NFL scouting combine, "I don't really compare myself to other players."

He might want to start since NFL teams are doing it right now. And Mariota is already starting a subtle slide down the draft board because of it.

Granted, nobody is predicting a Mariota slide. This draft is too starved for quarterback talent for that to happen. But NFL teams are going to make comparisons to his game. Every team has two prominent questions for quarterbacks: who are you similar to, and what kind of success have comparative players had in the pro game?

Right now, franchises are asking that question about Mariota. They want him in a box. They need him in a box.

Prior to his combine workout, here is what teams are seeing inside that box: a spread system/read-option style quarterback who spent a large part of his career standing straight up in the shotgun. Fewer three-, five- and seven-step drops. A lot of first-read completions. Few third and fourth progression completions. Plenty of improvising. Not a great deal of living inside the pocket.

That sounds a lot like Kaepernick and Griffin. There are similarities (albeit fewer) to Manziel, too. In short, it's an ugly box at the moment.

Of course, the decision-makers are saying the right things about Mariota. He has stated that he is going to run and throw at the combine, which teams always love to hear. That gets him the "competitor" sash, which is always given out to the elite quarterbacks who crank it up on a February day in Indianapolis. Tampa Bay Buccaneers general manager Jason Licht – whose team owns the first overall pick – praised Mariota for that very fact.

But Licht also said something that could be construed as a tipped hand. Asked about the difficulty of determining a "franchise" guy at quarterback, Licht offered this: "There are always challenges. Not to be broad here, but every player is a projection in the draft. There is no sure thing. You can kind of rate them, who's the most 'sure' of the group. Sometimes we do an exercise of, 'Which five guys do you know are going to be playing 10 years from now? Like, who would you bet on?'"

If the Buccaneers are playing percentages, the reality is that the success rate of traditional, pro-style quarterbacks (guys like Jameis Winston) – who made their college living stepping up inside a pocket and going through progressions – far outweigh the successes of quarterbacks who were grown primarily in a shotgun system.

Why?

Shotgun systems can take advantage of inconsistent speed and athleticism on the college level. In every game, coaches can usually find multiple areas to expose. In the NFL, that doesn't consistently exist. The advantage of finding open passing windows is significantly diminished. Almost every single defensive player on the field dominated with either speed or athleticism coming out of college. Defenses are far more complicated, forcing more progressions from the pocket and more decisions under pressure.

The college shotgun quarterback also must deal with playing under center, utilizing a huddle in a timely fashion and then dropping back at the same time he is working the math down the field. And when a player's skills are overly dependent on their legs? Injuries happen. Punishment happens. Watch all of Manziel's tape from the 2014 season. The legs that he thrived on in college were almost useless in the NFL. He spent more time running for his life than anything else.

The bottom line, defenses adjust fast in the NFL. And the focus on their adjustments almost always starts with the style of quarterback. Remember when the read-option offense was going to change the NFL, and guys like Kaepernick and Griffin were going to reshape the quarterback position? Like most new offensive wrinkles, defenses won in the long run. Rather than changing the game, Kaepernick is fighting Twitter battles over his offensive reads, and Griffin's starting job is seemingly hanging by a thread. As for Manziel, his team has been openly advertising its need for a starting quarterback for months.

None of this is to say that Mariota can't succeed in the pros. He showed up at the combine with a more NFL-ready body (6-foot-3 3/4, 222 pounds) than many expected. His hands also measured in the 9 ½ to 10-inch range that NFL teams prefer, coming in at 9 7/8. His film also shows a passing acumen that suggests a more developed touch than that of Kaepernick and Griffin when they were coming out of college.

There's also something to be said about bucking the "system" label as well. After all, there was a time most believed that Jeff Tedford quarterbacks couldn't make it big in the NFL. Then along came Aaron Rodgers, who made wicked strides. There's no saying Mariota can't be that guy.

With the draft less than three months away, a team like Tampa Bay is staring at some less-than-appealing realities. Mariota admitted Thursday that teams want to see him practice a huddle. Yes, a huddle. He didn't manage one consistently at Oregon. And he's got to work on his drops in the pocket, taking snaps under center, and making throws from between the tackles. All of which makes it seem less and less likely that he'll be ready to take off running when the season begins.

Yet, at this moment – until he changes something in the equation – there are a lot of nagging negatives on the ledger. While Winston has an avalanche of off-field issues to answer for, the reality is that his college film translates far better in the NFL world. And while physically Winston's waistline is not nearly as impressive, his arm has already shown the ability to make every NFL throw. Winston is also considered to be the more vocal, charismatic leader. And arguably only the Philadelphia Eagles have an offense that is purely suited to Mariota.

It's the start of the draft process. Teams still have plenty of time to fall into or out of love with someone's game. More skeletons can still be unearthed. Opinions can change. Guys have been known to slide out of the No. 1 spot in the draft and climb right back into the perch.

In essence, the box that is holding Mariota can still be shaped. But that's not easy. And at the very least, Mariota would do well to recognize who is sharing his box, and how to distance himself from the NFL struggles that come from inside it.