Yes, film trumps all ... but the NFL Combine matters. It's the only time when prospects can be easily compared -- both to other prospects in their class and those who came before them -- on a level playing field. 

If an NFL evaluator has two nearly identical grades on a receiver but wideout A runs a 4.46 and wideout B runs a 4.52 ... well, you probably can guess which player tends to move up the board.

And as always, there are a plethora of prospects who will make or break their draft stock at this year's combine. 

These 10 prospects have the most riding on the athletic exhibition in Indianapolis. 

Joshua Jackson, CB, Iowa 

Jackson's 2017 film is ridiculous. I mean, the guy had 18 pass breakups and eight interceptions, so he must have been doing more than a few things right. He played zone coverage amazingly well, flashed man-to-man ability, and has good size. Jackson looks like a No. 1 perimeter corner. But he'll likely have to run fast to be one of the first defensive backs selected. 

Last year, Marshon Lattimore was the first cornerback taken. He ran 4.36. The year before that ... Jalen Ramsey, 4.41. In 2015, Trae Waynes was the first corner picked. His 40 time was a blistering 4.31. Even the second cornerback picked in the last two drafts -- Marlon Humphrey, 4.41 and Eli Apple, 4.40 -- were all sub-4.45 guys.

If Jackson can run under 4.45, he'll scoot up boards and -- depending on how his combine compares to Minkah Fitzpatrick -- be in contention to be the first cornerback picked in the 2018 draft.

James Washington, WR, Oklahoma State

Washington was an electric downfield weapon his entire collegiate career. He's the only FCS wideout to accumulate 200 receptions and average at least 19.0 yards per catch in his collegiate career among all receivers dating back to 2000. 

But he's not quite 5'11", so he'll want to validate his film speed with timed speed at the combine. If he does that -- anything under 4.50 would be fine -- he'll essentially lock in being a first-round pick. 

If Washington runs slower than 4.50, he could fall into the top 10 picks of the second round. 

Calvin Ridley, WR, Alabama

Ridley was listed at 6-foot-1 and 190 pounds this past season at Alabama, and he looks slender on film. Despite being held back by the Crimson Tide quarterback situation during his career in Tuscaloosa, Ridley has been billed as a downfield threat. And he certainly created some explosive plays in college. 

So the weigh-in will be important for Ridley, as will the 40-yard dash (including the 10-yard split) and the jumps. He needs to showcase elite-level speed to cement himself as a Top 15 selection, which, at this point, he probably is. 

But if he's under 200 pounds, he's going to have to fly to reach expectations. Here's a rundown of sub-200 pound wideouts picked in the first round over the past three years and their 40 times: 

That's an average 40 time of ... 4.33. [insert Ric Flair woooo]

Overall, when factoring in all the positions, the 40-yard dash is overrated. Not for wide receivers. 

Hercules Mata'afa, DL, Washington State

Mata'afa is one of the most fascinating prospects in this entire class. No joke. He was listed at 6-2 and 252 pounds in 2017, almost exclusively played an interior defensive line position and wreaked havoc all season. 

Now, for as much as the league is shifting to smaller, faster defenders, Mata'afa will have an extremely difficult time playing defensive tackle at 6-2 and 252 pounds. Does he try to bulk up a bit and get close to -- or above -- 260 pounds with potentially risking some of his incredible burst and acceleration? 

Or does he come in right around his playing weight and look to transition to an edge-rusher spot? 

Either way, expect Mata'afa to crush the 40, the jumps and the agility drills. 

Ronald Jones II, RB, USC

Jones flies on film. Once he gets to the second level, he's a serious threat to go the distance. Track speed. And he has the vision and subtle agility to squeeze through small spaces between the tackles. 

At this point, he's widely considered the No. 3 running back behind Saquon Barkley and Derrius Guice

But for as impressive as he is on inside runs, his specialty is his home-run hitting speed. If he clocks a 40-yard dash time faster than Guice, he very well could be the second running back off the board, and get picked in the first round. Last year, eight running backs ran a sub-4.50. It's a distinct possibility Jones hits that 4.49 mark. It's important to remember though... Jones will likely weigh-in 10-15 pounds lighter than Guice and potentially 20 pounds lighter than Barkley.  

Rashaan Evans, LB, Alabama

In one of the best off-ball linebacker classes in a long time, Evans needs a quality combine performance to fortify his stock. The problem is, Roquan Smith is likely to test well at around 230-235 pounds and a shorter frame. Tremaine Edmunds and Leighton Vander Esch, two oversized linebacker prospects with freakish athleticism very well could test through the roof. 

That leaves Evans, who, will score points with teams due to his experience in Alabama's famed defense, but doesn't enter the combine as someone expected to perform amazingly in Indianapolis. 

In terms of size, he'll likely be somewhere between Smith and the Edmunds / Vander Esch duo, however the reputation of Crimson Tide linebackers -- while mostly good -- places him as a "downhill thumper," which is useful but a label trending in the wrong direction for today's wide-open NFL. 

Harold Landry, EDGE, Boston College

Landry was excellent in 2016. He finished his junior campaign with 22.5 tackles for loss and 16.5 sacks. In 2017, he had five sacks and eight tackles for loss in eight games before injuries hit. 

While his senior year film showed impressive flashes, he wasn't nearly as disruptive as he was in the prior season. 

For edge-rushers, the three-cone drill is the most vital. No other drill teases out a prospect's ability to bend and explode, two central elements in getting to the quarterback. Landry isn't armed with an array of passing-rushing moves -- most of his wins come via a tightly-bent speed rush. So he'll need to flourish in the three-cone drill in Indy. 

Depending on his weight -- and he's likely to be around 250-255 pounds -- the coveted 7.00 second mark is what he's aiming to beat. If he's a few tenths of a second slower, it won't totally plummet his stock though. 

Leighton Vander Esch, LB, Boise State

As previously mentioned, there's plenty of buzz about the show Edmunds and Vander Esch are going to put on at the combine. What's interesting though -- the two linebackers are similarly sized with similar film and appear to have comparable athleticism ... but Edmunds is widely believed to go much earlier than the Boise State product. 

If Vander Esch stays anywhere in the range of Edmunds in the 40, the jumps, and agility drills, he may not go ahead of the Virginia Tech star, but he'll have a distinct possibility of going in the first round. 

Christian Kirk, WR, Texas A&M

Some of Kirk's film -- particularly in the return game -- the wideout looks incredibly fast. In other instances -- mainly with the ball in his hands after a short completion -- he looks to be lacking in that department. 

Kirk is a wild card to go in the first round ... if he blazes in the 40-yard dash. In 2015, Will Fuller jumped into the first round with a 4.31 40-yard dash. John Ross was considered a first-round lock after his record-setting 4.22 last year. 

The Texas A&M star doesn't need to run that fast to go in Round 1, but the same rule applies for Kirk as it does for Ridley. If he's under 200 pounds, he'll need to burn up the 40 to be within the first 32 selections. 

Even if that's not the most realistic scenario for Kirk, there's healthy competition to be the fourth wideout picked after Ridley, Courtland Sutton and James Washington. A 40 time under 4.50 would be a big boon for Kirk in that race.

Marcus Davenport, DE, UTSA

Right now, Davenport is considered a prospect cemented in the first round. He was the talk of the Senior Bowl in January and his tremendous size, length, and athleticism pop on film. 

Because he's not carrying 270-plus pounds and is over 6-5, Davenport has the frame to dazzle at the combine. He should perform well in all the "explosion" drills, and a three-cone time under 7.30 would be fantastic for his taller stature. 

If he's one of the clear-cut winners among the edge-rushers, Davenport will start to garner serious Top 15 talk and, depending on where his combine ranks among his contemporaries, would fortify himself as the second edge-rusher picked after Bradley Chubb.