Over 300 players were invited to the NFL combine this year, and a few hundred more will make their way onto teams’ draft boards come April. Sorting through all of that information might seem impossible, but, well, draft analysts and talent evaluators have to do it.

Beyond the sheer number of prospects, this year’s class poses plenty of difficult scouting questions. Ohio State’s pair of one-year defensive back starters Marshon Lattimore and Malik Hooker are both slated to go early in the first round, but how do scouts draw conclusions from such a small sample size of plays? Then there’s Jabrill Peppers, who played on both offense and defense at Michigan; how do they know where he belongs in the NFL and what kind of an impact he’ll have wherever he ends up? As for Western Michigan receiver Corey Davis, how do evaluators factor in the lower level of MAC competition he dominated against for four years?

In short, scouts are not watching the same thing you’re watching. You might see Stanford’s Solomon Thomas curl around the edge and sack a quarterback or Florida State’s Dalvin Cook bounce to the outside and take a handoff 50 yards for a touchdown; anyone watching that same footage will see the same thing. Scouts, on the other hand, aren’t looking at what those players did; they’re looking at how they did it.

So, what qualities are scouts looking for? I talked to some draft experts to find out.

1. Can He Do the One Thing Every Pro Has to Be Able to Do?

For each position, there’s always one thing an evaluator is looking for above all else in order to see if said prospect is an NFL-quality talent.

When NFL.com’s Lance Zierlein watches running backs, he wants to know whether that player can create yards for himself, independent of the offensive line.

“Look, any running back can get what’s blocked for him,” he said. “But if you want to find a running back that can transcend his offensive line, you have to ask yourself: Is he elusive? Does he run with power? Does he have the speed to pull away and become a home run hitter? If a guy doesn’t get a check mark in any of those three factors, he’s probably just a guy.”

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The same logic applies to the defensive line, according to NBC and Rotoworld’s Josh Norris.

“There has to be something dynamic about them,” he said. “On the outside, you really have three steps that you can take to get an advantageous position on offensive tackles, and then, once you do that, you need to have the flexibility or short area agility to either bend around the corner or put your foot in the dirt to work inside. If you have great straight-line burst off the line, but you have no bend, then all you’re going to do is get pushed around the pocket.”

Conveniently, this tweet about newly signed Indianapolis Colts pass rusher Margus Hunt popped up on my timeline while I was chatting with Norris:

For middle linebackers, according to Dan Kadar of SB Nation’s Mocking the Draft, their first step always has to be in the right direction.

“Luke Kuechly is the perfect example of this,” he said. “I don’t recall him ever having a false first move. That’s the first thing I look for, because no matter how fast a guy is, no matter how long or athletic they are, if they go in the wrong direction initially and have to correct themselves, they’re blown out of the play.”

And when it comes to receivers, NFL.com and Backyard Banter’s Matt Harmon said, the first requirement isn’t something you can pick up on from a 15-second clip; instead, it’s about consistency.

“I’m very consumed with what I would call ‘highlight bias,’” he said. “When you see a receiver make a great contested catch, you say, ‘Oh, this guy is a great contested-catch receiver!’ But then over a multiple-game sample size, he’s not doing that. I want to see the guy be the same player on a route-to-route basis.”

2. Does He Do the Little Things Well?

Once the baseline requirements are established, you can start looking for those harder-to-spot things that might push a prospect from “potentially average NFL player” to “potential star.”

For example, there are plenty of über-strong defensive linemen, but the ones who carve out long NFL lives are the ones who can do more than just bull-rush. Former Giants, Jets, and Eagles scout Dan Hatman, who’s now director of scouting development at The Scouting Academy, said he looks not at hand use but “hand timing” when evaluating defensive linemen.

“I break hand use down into three categories: timing, placement, and strength,” he said. “Here’s my argument: If you don’t have the first one, the second two don’t matter. If you don’t time when you release your hands, the placement and the strength go away.”

Hand timing, Hatman said, isn’t necessarily something you can easily learn, either. It’s an instinctual talent, and it can separate a great defensive lineman from an average one.

“At some point [in the play],” he said, “you actually have to let go of your hands and release them — fire them — to hit your key [target on the offensive lineman]. If you fire them too early, you get overextended. You’re lunging, you’re off balance. If you’re too late, the [lineman] owns your chest. So there’s like, this perfect moment. … It’s so hard, it’s like teaching Barry Sanders when to make a cut. You don’t teach that; the guy just knows.”

For offensive linemen, Zierlein is more concerned with hand strength.

“[Look at] guys like [Chicago Bears center] Cody Whitehair last year,” he said. “He had vise grips for hands. It’s similar to wrestling, because they can control your shoulders, and if you can get in and latch in, then you can kind of do what I call ‘ride the bull.’ Those guys can stay connected to their blocks longer and sustain them.

After seeing whether a running back can create for himself, Zierlein will look at how quickly he can process the information in front of him on a given play.

“I watched a guy named Joe Yearby from Miami,” he said. “I talked to a scout today who said, ‘That guy stinks,’ and thinks he can’t play. I think that scout is going to be wrong. [Yearby] didn’t go to the combine, but I’m telling you, when you watch him play, he never changes his speed. He can process quickly what he sees in the hole.

“The guys that see things quickly are able to play faster. And if you can play fast at running back, I think you have a chance to make it in the NFL, provided you have a certain level of quickness and a certain level of either strength or elusiveness.”

When it comes to pass catchers, Kadar said that aggressiveness often gets overlooked.

“Some guys are just content in running their route and letting the ball come to them instead of being a killer and bodying up on a defensive back to go up and get the ball,” he said. “I really like the guys that have some nastiness to their game, like Mike Williams of Clemson. I know he’s going to run slow, if he runs a 40. [Williams clocked in at the 4.57-second range at his pro day.] And I know that he had a pretty not-great vertical at the combine (32.5 inches), but man, he’s aggressive. He just goes after it. He’ll beat guys on jump balls, he’ll be more physical.”

3. Does He Have Any Deal Breakers? And Should It Even Matter If He Does?

While scouts are usually looking for what a player does well, they also have to keep an eye out for the things each prospect struggles with. Sometimes, an inability to do something will lead an evaluator to drop a prospect completely off his board.

“A lack of vision is a deal breaker” at the running back spot, Zierlein said. “You have to have at least functional vision. You have to have a feel for the holes, because it’s not like college. You don’t get to run out of shotgun, get inside handoffs against five- and six-man boxes all day.”

For the offensive line: “If a guy’s not functionally strong enough, it’s like not being able to hit a fastball in baseball,” he said. “At the major league level, you can’t make it if you can’t generate enough bat speed to to hit a fastball. It’s the same with offensive linemen. If you can’t muster enough functional strength to hold your ground, at least to a certain level — it doesn’t have to be great, but it’s got to be to a certain level — they will just continue to bull-rush you.”

Yet, while most evaluators have versions of those red-flag traits in college prospects, some consider the concept of the “deal breaker” to be myopic. For those scouts, it’s more important to look at what a player can do well rather than focusing on where he fails. Norris has championed a “where they win” mantra in his evaluation process.

“Most NFL teams evaluate against a checklist,” he said. “So, they’ll go through, and, say it’s a running back: Does he break tackles? Does he have a jump cut? Can he pass-protect? Can he catch passes? Does he have straight-line speed, big-play threat? There’s stuff for every position.

“To me, when you evaluate against a checklist, you’re evaluating against perfection. No matter what, you’re going to end up with far more negatives than positives. And if you have a negative sense of a player, then what good is that to a team? All it comes down to is identifying where a player succeeds, where he wins. If a team needs something in this area, it’ll allow them to win.”

Meanwhile, Harmon created the “Reception Perception” — a methodology for scouting receivers that tracks the success rate of every route they run against every type of coverage — in part to eliminate the stigma that comes along with, say, a receiver who has a few too many drops.

“I have a problem how we often talk about drops,” he said. “People see a bunch of drops, a negative outcome, and they can’t get that out of their head. I think that my data, and the way that I collect it, by sampling a ton of routes and a ton of plays, that kind of eliminates that temptation to have those deal breakers.”

4. What’s Missing From the Tape?

In the court of law, eyewitness testimony is often unreliable and inaccurate, and pure tape scouting should probably be treated with a similar amount of skepticism. For one, evaluating a player just by watching his games requires a certain amount of knowledge of the context of each game — factoring in the level of competition, understanding the objective for each prospect in a given play, etc.

When starting on a film study on a defensive lineman, Hatman said, it’s essential to know whether it’s a two-gap system or a one-gap front and whether it’s an attacking scheme or a wait-and-see system.

”All that stuff becomes important, because if you watch your first couple snaps of a defensive lineman, and you go, ‘His get-off isn’t that good!’ but he’s in a reactive, two-gap front? Well, no wonder his get-off doesn’t look good,” he said. “None of those things allow his get-off to look good.”

Without that information, what you’re seeing on tape is close to meaningless. And on top of the play-calling and scheme context, scouts have to remember that the player they’re watching isn’t going to be ported into an NFL game in the same form.

It can be a problem, Zierlein said, if you’re “relying too much on who [these players] are, rather than who they’re going to be. You have to assume a certain level of coaching. But really, this is who they are right now, and you’re supposed to be looking for what the tape says they can become.

“It’s been one of my problems: I beat guys up for their deficiencies now, rather than assuming some of those deficiencies can be corrected, at least to a functional level.”

Scouts can avoid these pitfalls and up their evaluations’ accuracy by using analytics, athleticism metrics, and any other context available. Of course, there’s no foolproof way to avoid the next Trent Richardson or Vernon Gholston, but the best analysts and scouts draw on as many different resources as possible to add a frame of reference for what they’re seeing on tape.

“Good film scouting generates good questions, not good answers,” Hatman said.

In other words, it’s a starting point, rather than an end.

“I’m going to leverage my contacts on campuses, at pro days, the combine, Senior Bowls, or whatever else to answer those questions,” Hatman said. “We built these events for a reason. You consider everything you can learn about these players. It’s how much you weigh it that really makes a difference.”

With the draft a little more than a month away, Hatman and his counterparts inside the league don’t have much more time to decide what matters. But whatever the NFL scouts decide does matter will determine how everything plays out in April. Well, everything after the no. 1 pick. You don’t have to be a scout to figure out that Myles Garrett is better than everyone else.