Like it or not, the NFL Scouting Combine can significantly affect where a player gets drafted in April.
The 40-yard dash in particular tends to significantly influence where a player is drafted, with wide receivers, running backs, and cornerbacks most affected.
If you're not convinced, just ask Darrius Heyward-Bey and Michael Crabtree. Granted, Al Davis is known for making ill-advised first-round picks, but Heyward-Bey's stock was affected significantly by his fast 40 time.
Crabtree could have been a top-five pick, but not running a 40-yard dash at the combine led to question marks about his speed.
Heyward-Bey, picked ahead of Crabtree, did not pan out—and he is a great example of putting too much stock into a 40-yard dash time.
Chris Johnson is a more positive example. He was picked 24th in Round One in 2008, despite being ranked fifth among running backs and 41st overall by Scouts Inc. Johnson ran the fastest 40 time at the combine at 4.24 seconds.
Regardless of whether it's foolish or not, the fact remains that 40-yard dash times can affect draft stock significantly. Players who choose not to run the dash—or run poorly—often see their stock drop; players who run well often see their stock rise.
This year, there are a few players whose stock could be significantly affected (some positively, some negatively) by their 40-yard dash times.
Players Who Could Be Affected Positively
These are players who will likely maintain their current stock with a solid 40 time, but they have a great chance to improve upon it with a great 40 time.
1. Jacoby Ford—WR, Clemson
Ford is seen as an undersized burner who will likely be a solid returner, but not a No. 1 or 2 receiver. However, Ford has great track speed and could run a sub-4.3 dash. If he is able to do that at the combine, he will significantly improve his stock.
2. Riley Cooper—WR, Florida
Cooper had a solid senior season at Florida, but he is still seen as a mid-round prospect. Cooper himself and a number of others think he can run faster than his public 4.5 time. If he is able to run a 4.4, Cooper could bump his stock up a round.
3. Perrish Cox—CB/S, Oklahoma State
Cox had been rising in many scouts' minds, but his stock took a huge hit at the Senior Bowl. Cox missed curfew twice and is now seen as a red-flag player for character issues. Cox has the ability to run a sub-4.4 on a good day. If he can do that, he could gain back some of his lost stock.
4. Taylor Mays—S, USC
Mays, once considered a top-10 pick, has fallen to a fringe first-rounder. There are many concerns with Mays' ability to play the safety position at the NFL level. With rumored sub-4.4 speed, Mays will have to prove it to improve his stock.
5. Ricky Sapp—DE/OLB, Clemson
Sapp is likely the fastest outside linebacker/defensive end in the draft this year. Right now, Sapp is a fringe first-rounder, but more likely a second-round pick. Sapp has the ability to run a sub-4.5 dash; if he can do that, he may solidify a first-round grade.
Players Who Could Be Affected Negatively
These are players who have a high likelihood of running a poor 40-yard dash—and they need to run a solid time to maintain their current draft stock.
1. Brandon Spikes—LB, Florida
Spikes had a phenomenal college football career. However, his No. 1 question mark is his top-end speed. Spikes plays faster than he is because of his quickness, but his 40 time could hurt his stock. If Spikes can't run below a 4.75, his stock could take a hit and push him deeper into the second round.
2. Jordan Shipley—WR, Texas
Shipley had a phenomenal senior season for Texas. However, he is undersized and does not possess great top-end speed. If Shipley runs in the 4.55 range, his stock will likely take a hit. Teams have trouble with drafting undersized wideouts without great top-end speed.
3. Toby Gerhart—RB, Stanford
Gerhart had a season for the ages at Stanford, and he could very well end up being a solid NFL running back. However, his 40 time could be as high as 4.6 seconds. If that is the case, his stock will likely slip.
4. Javier Arenas—CB, Alabama
Arenas has seen his stock go up after a solid senior season. Arenas made a splash at corner and in the return game. Despite being a solid return man at Alabama, Arenas' 40 time could end up in the 4.55-4.65 range. If this is the case, he may lose his added special teams value in the draft.
5. Charles Scott—RB, LSU
Much like Gerhart, Scott is a big inside runner with below-average top-end speed. Scott will likely run a time in the 4.6 range. Regardless of how teams view him as a solid inside runner, a poor 40 time for a running back never helps his draft stock.