With Oklahoma's Joe Mixon declaring for the NFL draft, John Clayton evaluates how Mixon will be evaluated by NFL teams. (2:10)

Monday was the deadline for college underclassmen to declare for the 2017 NFL draft. In making the decision to forgo their final year of eligibility, some cited league assurances that they would be selected in the top two rounds.

Oklahoma running back Joe Mixon, for example, said he received a first-round grade from the NFL -- despite a yearlong suspension for assault in 2014 -- before filing his paperwork.

Where do these grades come from? Who issues them? And how accurate are they?

Let's take a closer look at the NFL's College Advisory Committee (CAC), which provides free evaluations for up to five players per school in every draft season. The advice isn't always heeded, and it's not 100 percent accurate, but it still serves as important third-party information.

In a recent telephone conversation, NFL executive vice president of football operations Troy Vincent said the ultimate goal of the program is to "provide the best information for the student-athletes to make an informed decision."

If nothing else, it is a credible tool for players and their advisers to cross-reference with information and projections they've heard elsewhere.

"We're trying to cut through the filters," Vincent said.

Who is on the committee?

The process is managed by Vincent's office and includes a representative of the league's two scouting combines -- National Football Scouting and BLESTO -- as well as one evaluator from each of the league's 32 teams. The profile of the team rep varies per club, but Vincent characterized all of them as "decision-makers."

How many players apply for an evaluation?

The range since 2010 has been between 149 and 214 players every draft season, according to league data. If on a rare occasion there are more than five interested players from a single school, the college coach decides whose applications to send.

What attributes are the players evaluated on?

"It is a true football assessment only," Vincent said.

In other words, the committee does not attempt to project the impact of any off-field or medical factors on the player's ultimate draft position. In Mixon's case, the review indicated his skills were commensurate with (presumably) a first-round pick. (The NFL does not confirm individual assessments.)

That's a separate opinion from how teams might downgrade him for an incident in which he punched a woman, breaking her jaw, eye socket and cheekbone. Video of the incident was made public over the winter.

What the committee is telling a player like Mixon is that he is a first-round physical talent absent any mitigating factors.

What process does the committee use to evaluate?

In most cases, scouts' evaluations of underclassmen are well underway by the time applications start arriving in mid-December. Each team representative, and both scouting services, provide individual reports on the players. Vincent's office forges them into a consensus grade.

What information do the players receive?

How Accurate Are These Evaluations? Here's a look at the accuracy of the College Advisory Committee and its evaluations for first- and second-round prospects, including the number who were drafted in the first two rounds: Year CAC Accuracy First 2 Rnds 2016 76.0% 19/25 2015 90.0% 18/20 2014 90.9% 20/22 2013 85.7% 18/21 2012 82.4% 14/17 2011 93.3% 14/15 2010 72.2% 13/18

The response is relatively simple. Players are advised, in a letter to their head coach, that they are assessed as either a first-round pick, a second-round pick or one who is advised to remain in school. Vincent also makes himself available for telephone conversations.

"We don't get into a lot of specifics," Vincent said. "This isn't the place to tell student-athletes what they need to improve on or where they're lacking or whatever. It's intended as the best objective assessment we can provide."

The CAC doesn't provide draft projections beyond the second round?

Not anymore. Vincent began limiting the answers to the first or second round after the 2014 draft. Research showed that accuracy dropped off significantly beginning with third-round projections.

How accurate are the projections now?

Since 2010, players who received a first- or second-round evaluation and declared for the draft were selected by the end of the second round 84.1 percent of the time. Yearly accuracy rates are in the chart.

Do all underclassmen request these assessments?

No.

In 2015 and 2016, the first two years of the streamlined approach, 38.2 percent of underclassmen declared for the draft without applying for an evaluation. (Numbers for 2017 haven’t been tabulated yet.)

What happens when players don't heed the advice they're given?

Here's what we can tell you.

From 2015-16, 322 players were evaluated.

Of that total, 73 declared after being advised to stay in school.

The average draft position of that subgroup was the fifth round. Twenty went undrafted.

Can it work the other way?

Sure. Of the 73 who declared after being advised to stay in school, 11 were drafted in the first or second rounds (15 percent).