Explaining to my wife why I need to watch the NFL Combine every year becomes a very introspective experience. Telling a casual observer how and why athletic testing and measurables matter makes superficial sense. But those of us who live and breathe this know the truth. As NFL teams get access to more data and the year's biggest prospects opt out with more frequency, I start asking myself why I should watch the NFL Combine. Sure, marking down testing numbers and speed scores in a prospect's profile is essential, but how much does it actually translate to on-field NFL production? I'm not the first to ask the question; many have done deep dives to answer it. And the correct evaluation is somewhere between "it matters a little bit" and "it doesn't matter at all."

Take Iowa's Kaleb Johnson, for instance. Johnson has been a consensus top-five running back in this year's class, with many analysts ranking him as their RB2. His collegiate career was highlighted by big plays. Iowa's GPS tracking system clocked him running over 21 miles per hour on multiple runs last year, and even one above 22. His 28 breakaway runs of 15-plus yards were the third-most in the FBS in 2024 behind only Ashton Jeanty and RJ Harvey. But he ran a 4.57-second 40-yard dash on Saturday. Of the 24 prospects to participate in that drill, only four ran slower than Johnson. So, what do we do with that information? Do we knock him way down our rankings? Do we ignore it?

Every analyst weighs NFL Combine results differently, and here's how I use them in my process.

1. Adjust for weight

This is probably the biggest thing the average fan misses. Not all 40 times are created equally. A guy running 4.57 at 224 pounds is more impressive than a guy running in 4.45 seconds at 193 pounds. And we can quantify those Speed Scores with a very simple formula.

Luckily, our friend JJ Zachariason does that work for us, applying size-adjusted speed scores to each prospect.

Here's a list of the running backs who ran 40s today alongside their Speed Score. Generally, anything above 100 is solid. Below 90-92 is a red flag (sometimes). Just one data point, but, once again, this class is looking good. pic.twitter.com/a4Tnskbqge

— JJ Zachariason (@LateRoundQB) March 1, 2025

So, while many people might be turned off by the 4.57 that Kaleb Johnson ran, his size-adjusted speed score of 102.71 is still competent. And look at the guy directly below him in Speed Score. Tahj Brooks actually ran faster than Johnson, but running 0.17 seconds faster at 10 pounds lighter is technically less impressive. We'll revisit Tahj Brooks in a bit. But the first step in looking at 40 times is to adjust for size.

2. Factor in other NFL Combine drills

40-yard dashes are fun and increase television ratings, but the reality is that the correlation to career-long fantasy production is almost nonexistent.

Tej Seth of Sumer Sports recently looked at what drills correlate most to production for running backs, and the 40-yard dash ranked dead last.

To no huge surprise, three-cone and shuttle drills are more important for running backs. Think about it: the majority of a running back's touches will be through traffic where lateral quickness, acceleration, and deceleration are paramount. Very few NFL running backs are ever afforded the opportunity to run 40 yards in a straight line during a game.

And while Kaleb Johnson didn't partake in those drills, we can look at Tahj Brooks as a guy who did. And he checked those boxes. His size-adjusted speed score of 102.54 is passable (just behind Kaleb Johnson's), but he showed out in the three-cone and shuttle drills, which should not be ignored. An "elite" composite agility score is very important for running backs, even more than the 40-yard dash.

Thanks, as always, to Kent Lee Platte for all of the work he does on gathering information into his Relative Athletic Score player cards. You can see that while Brooks' size, speed, and explosion grades are all "good," his composite agility grade is considered "elite," and we know those drills matter most for running backs.

For reference, Kaleb Johnson did not participate in the agility drills.

3. Re-rank inside tiers

Looking at these two players, Kaleb Johnson and Tahj Brooks, and how they performed at the NFL Combine, is it now time to move Brooks ahead of Johnson because of his elite agility grade? After all, Brooks had better athletic measurables, and they put up similar numbers last year. So we move Brooks ahead, right? Of course not!

This is just a tiny piece of the puzzle. Johnson is a year and a half younger than Brooks. He averaged over a yard more per carry in 2024. He has an advantage in size and breakout age. His age-adjusted production profile is much more impressive.

We want to use the information from the Combine to make microchanges inside tiers. If you had Omarion Hampton, TreVeyon Henderson, Quinshon Judkins, and Kaleb Johnson in a tier together, Johnson would probably fall to the bottom of that tier after Saturday. And if you had Tahj Brooks alongside Woody Marks and Kyle Monangai, you could safely move Brooks up inside that tier.

Like analytical modeling, film watching, and draft capital, the NFL Combine results are just another piece of information to use in prospect grading and ranking. To completely ignore this weekend would be just as silly as using it as your primary guide.

Let's discuss some of the biggest risers and fallers at the running back position from this weekend.

NFL Combine Risers

Omarion Hampton, North Carolina

Hampton was already a favorite among many analysts, but the buzz he's garnering after this weekend is impossible to ignore. Tony Pauline reported that some teams have Hampton over Ashton Jeanty. Hampton has been well-known as a workout warrior, and showing up to the Combine at a tight 221 pounds and a hair under six feet corroborated that. He went on to crush his testing. His 4.46 40-yard dash pushed him to this class's third-best Relative Athletic Score (9.78) and the 43rd-best of 1,909 running backs graded since 1987. This year's Draft will have other good backs, but Hampton should be the consensus RB2 after this weekend.

Quinshon Judkins, Ohio State

Judkins and his backfield mate TreVeyon Henderson were both tough players to evaluate. The pro-style offense run by Ohio State kept both backs in limited roles that maximized their skill sets. Judkins regularly got early-down touches where he could showcase his violent running style. Henderson would come in on passing downs where he could get in open space and rip off big plays. There were questions about Judkins' athleticism, as his role pigeon-holed him into being an early-down thumper. Like Hampton, he weighed in at a hefty 221 pounds. But his 4.48 40, 38" vertical, and 11' broad jump answered our questions about his speed and explosion. He clearly possesses both. Checking those boxes to accompany his exciting film should have him soaring up draft boards. Henderson had a great weekend as well. And the only reason he isn't listed as a "riser" is that most analysts were already high on him coming into the weekend.

Cam Skattebo, Arizona State

There are still questions about Skattebo's long speed. And opting out of running the 40-yard dash will have many awaiting his Pro Day. But in the explosiveness department, no running back looked better than Skattebo this weekend. A 39.5" vertical and 10'3" broad jump both qualify as elite. He did that at an impressive 219 pounds. Skattebo will likely shed a few pounds to run faster at his Pro Day, but his explosive measurables will assuredly pique the interest of many teams looking for a hard-hitting early-down grinder.

RJ Harvey, Central Florida

Another uber-athletic running back from this class, RJ Harvey, checked all of the boxes we wanted to see this weekend. We knew he was small, and he expectedly measured in at 5'8" and 205. But a 4.40-second 40-yard dash, 38" vertical, and 10'7" broad jump all qualify as elite. His Relative Athletic Score of 8.94 just misses the cut as a 90th-percentile all-time mark. His best traits are in his agility, so a less-than-stellar shuttle isn't ideal. But for a guy who was typically mocked as a Day 3 pick, Harvey did enough on Saturday to potentially sneak in as a Day 2 guy.

DJ Giddens, Kansas State

If you're getting sick of me talking about running backs posting historic Relative Athletic Scores, I'm sorry. But this class is good. And it's deep. Giddens posted a 9.78 Relative Athletic Score, identical to the aforementioned Omarion Hampton. He weighed in a bit light for his height (212 pounds at over 6 feet), but elite speed and explosive grades make him an alluring target for a running-back-needy NFL team. While Saturday's testing didn't answer the questions about Giddens' ability to play through contact, the speed and explosion alone is worth taking a chance on.

Bhayshul Tuten, Virginia Tech

Tuten's 4.32-second 40-yard dash, 1.49-second 10-yard split, and 40.5" vertical all led this year's running back class. His 10'10" broad jump ranked fourth. Many people were expecting an exciting day from Tuten, but he absolutely stole the show on Saturday. Of course, the downside here is his size. Tuten measured in at 5'9" and 206 pounds. But in a league skewing toward speed over size, expect to see a team reach for Tuten in April's Draft.

Tahj Brooks, Texas Tech

Brooks weighed in at 214, much less than the 230 Texas Tech listed him at. And while his age is certainly a concern, elite scores in the shuttle and three-cone shouldn't be ignored. Brooks' film shows that he's got a masterful understanding of gap manipulation and footwork. The agility composite scores and on-field drills will almost assuredly get him drafted, even if his age pushes him to Day 3.

NFL Combine Fallers

Kaleb Johnson, Iowa

Johnson isn't falling to Day 3. His draft stock isn't going to tailspin. But for a guy who had questions about his long speed coming into the NFL Combine, Johnson left his doubters wondering. While his film and college production are impossible to ignore, great weekends from Omarion Hampton, TreVeyon Henderson, and Quinshon Judkins will likely push Johnson to the bottom of that tier.

Jordan James, Oregon

A 4.55 40-yard dash isn't terrible. But doing it at 5'9" and 205 is. James' 95.66 size-adjusted speed score ranks fourth-worst in this class. On tape, James regularly showcases quick-twitch movements and breakaway speed. But for whatever reason, that wasn't on display this week. Poor athletic testing and a small frame are a combo most NFL teams look to avoid. And compared to his peers this weekend, it's hard not to view James as a significant faller.

Woody Marks, Southern California

Like Jordan James, the raw drill numbers in a vacuum aren't a death knell. But the subpar athleticism coupled with below-average size might be. Per Kent Lee Platte's Relatively Athletic Score, Marks' size is "okay" with "good" speed and explosive grades. The only agility drill he partook in was the shuttle, and he posted an underwhelming time of 4.24 seconds. Marks has an out to a fantasy-relevant role as a pass catcher, but his lack of athleticism could put a severe cap on his ceiling.

There might not be a running back from this class with a more tenacious playstyle than Monagai. He's a bruising back who seems to get better with contact. But he showed up very small (5'8", 211), and his 4.62 was the worst among the entire running back group. His explosive testing wasn't great, either. In a world where NFL players get more athletic every year, Monangai ranks in the bottom half of Relative Athletic Scores dating back to 1987. He had a fun style that made him a trendy sleeper, but his awful NFL Combine performance could cause him to go undrafted.