INDIANAPOLIS, Ind. -- Scouting and projecting players from college to the NFL is a vexing proposition. There's a reason that NFL general managers get paid the big bucks and personnel departments league-wide have to navigate the minefield of the NFL Draft each year in building the foundation for winning rosters.

As a basic concept, it's tough enough to scout college players -- you're dealing with human beings. As Seahawks GM John Schneider said on Wednesday, "the hardest part of scouting is knowing what's truly in a man's heart." People change. Motivation matters. Resiliency and grit can be just as important as talent.

But over the last decade, the biggest challenge for talent evaluators is the proliferation of the spread offense in college football. It means an already tough projection becomes almost guesswork for NFL teams when trying to decide if a particular player will be a good pro.

This was a common refrain in Indianapolis at the NFL Combine on Wednesday.

Speaking a new language

Gary Kubiak, head coach of the Super Bowl Champion Broncos, addressed this concept when asked about the future of the quarterback position in Denver. "A lot of [scouting quarterbacks] is projecting guys going under center," said Kubiak. "I know that sounds simple, but that is a little bit more of a conversion than you would think."

The timing changes. The amount of time a quarterback has to look at the defense changes; he turns his back on them in some cases. The footwork changes. It can be difficult to adjust to because the NFL is a much faster game.

"I think [the challenge becomes] studying guys that play in the gun the whole time," Kubiak continued, "trying to project them to what you do, making the conversion, how quick they can make it, it might be a little harder as a coach to make that decision as compared to watching a guy do the type of things that you do for three or four years in college. I think that's part of the tough part. You're looking for the ability to do things more than anything.

"It's your job as a coach once you get that to fit them to the type of system for what they do best to what your team does best."

It can be a crap shoot. And the physical skills -- footwork, throwing from different angles, the play-action fake, etc., are just the start of that.

Schneider talked at some length about how a spread offense quarterback who, like the rest of the offense, takes his playcalls from the sideline, will have to learn "a new language" in calling pro-style plays in the huddle. You have to learn how to speak "West Coast Offense." Playcalls can be long, tongue-twisting and very confusing. The quarterback has to command respect in the huddle, and it doesn't inspire a ton of confidence if he can barely remember how to call a play.

As Schneider said, it makes evaluating quarterbacks for the NFL kind of difficult, because a lot of guys are "looking over at the sideline and seeing pictures of Daffy Duck and stuff" to find out what they're running.

That's why teams often look at other attributes during the Combine process.

"There's so much that goes into [the quarterback] position that you can't see on film," said 49ers GM Trent Baalke. "That's why you've got to get the coaches with him, sit down, talk ball, do as much research into their work ethic, their preparation habits, their intelligence."

Quarterback isn't the only position group that presents a challenge. The frequent use of the spread offense affects the evaluations of nearly every position.

"It is obviously a hurry-up," explained Steelers GM Kevin Colbert. "There's usually not a huddle, there's not a lot of adjustments that are made, there's not a lot of sight adjustments that receivers have to make. So I think there's a huge learning curve and it just takes a little longer.

"The colleges won't change, because they're doing what they need to do to win football games. It's our job to take the talent and work with it, but it's a little longer than if they're coming from a traditional offense for sure."

It's a difference in style that can be seen across the board.

"It really affects everything," said Colbert. "The offensive line plays different, the receivers are different. The tight ends, instead of being attached to a formation, they could be flexed in the slot and they're used for the blocking on the perimeter. The running backs have different reads, they have different run lanes."

Learning to block all over again

Titans GM Jon Robinson added that offensive line is very difficult to evaluate as well.

"You see the college game and the tight ends, most of those guys now are flexed out," he said, "and a lot of the offensive linemen, they're not necessarily asked to run off the ball and sit a guy up and try to move a five-technique three yards down the field. They're kind of asked to just zone and occupy and let the backs cut off the blocks. So you really have to dig through those plays where you can really see him unroll his hips and dig his cleats in and really get moving."

It's a quick-strike, finesse game vs. a straight ahead, powerful smashmouth style. The offensive line issue was a very common complaint.

"It is more difficult, I think, because of the types of things [offensive linemen] are doing," said Kubiak. "Especially watching them in the run game. When they are in the spread game it's a little bit of a different type of run game as far as watching a guy come off the ball and power-type football and those types of things. I think evaluating their football knowledge [is important]."

As Raiders head coach Jack Del Rio pointed out, it's not just an offensive lineman's responsibilities in run game that can change going to the NFL. It can be a completely different technique.

"What you see are fewer and fewer college offensive linemen getting in three-point stances and doing some of the combination blocks we do in the NFL," said Del Rio.

Cardinals head coach Bruce Arians pointed out that it's really a matter of re-teaching linemen the basics: "You're drafting a guy right now coming out of some colleges that haven't been in a three-point stance since high school, and you're going to pay him a ton of money. It's fundamentals that we're going back now and have to teach. We never had to teach it before. Great athletes. The athletes are much, much better, but the fundamentals are worse than they've ever been."

Take Los Angeles Rams lineman Greg Robinson for example. The second overall pick in the 2014 Draft, a star at Auburn, he was (and is) a physical freak of nature, but his development has taken quite a bit longer than expected based on his inexperience in a pro-style system. It doesn't help that the Rams moved him around to different positions at the start of his career.

On the other side of the coin, take Rams tackle Rob Havenstein, who is decidedly not a physical freak of nature. After being selected in the second round last year, he was handed the starting right tackle job and excelled in that role as a rookie. He had the advantage of being well versed in a pro-style system coming out of Wisconsin. Many Stanford alums share the same short-term advantage.

Patience is a virtue

"We drafted D.J. [Humphries] last year knowing we were going to redshirt him because we had so much to teach him," explained Arians, on the Cardinals' first-round pick. "If we threw him out there, he was going to fail. Once they fail, it's hard to get those scars off. He didn't dress a game -- purposefully -- just to get better and better. Going against guys like Dwight Miller and Calais (Campbell) in practice, he got better every week. I think next year he'll be ready to play."

Washington State tackle Joe Dahl, who projects as a guard in the pros, talked to reporters Wednesday about learning to play out of the three-point stance and his comfort level with that. Coming from Mike Leach's air raid offense means that Dahl is going to have to start pretty much from scratch in extended pass-protection sets and especially in the run game. The same could be said for Texas A&M tackle Germain Ifedi and Texas Tech tackle Le'Raven Clark, for instance.

If a team takes a spread offensive lineman early, don't get your hopes up that he'll immediately become a star in his new system.

"The way we play in the National Football League, it's always a projection," said Arians. "Any time you're evaluating college players, regardless of the system, it's a projection. That's part of the business and that's what makes it fun, difficult and challenging."

College coaches and programs aren't responsible for preparing their players for the NFL. They're responsible for winning games, and with limited development time, the spread offense has been extremely effective. Whether it means changing the playbook, giving players more time to develop or some combination of the two, the NFL has to find a way to adapt.