All other things being equal, you'd prefer players be faster rather than slower. So we make note of 40 times at the combine, and they can determine if players are first- or second-round picks, or much later. The running backs ran last Friday, and consensus top back Saquon Barkley impressed with a 4.40.
You can check running back 40 times at this link. Best was N.C. State running back Nyheim Hines (4.38), though he won't top anyone's draft board at the position; a 5-foot-8, 198-pound back. Barkley had the 4.40, and two other backs likely to come off the board in the first three rounds (Louisiana State's Derrius Guice and San Diego State's Rashaad Penny) also put up sub-4.5 times.
We keep track of official 40 times in a file, and add in estimates from players without an official time. Some recorded their times as their various college pro days (typically faster than their official times), some didn't run at all in the evaluation process, due to injury or recovery (e.g., Willis McGahee), so the times are just guesses, or provided by the college or player.
So it's not an exact science, but it at least gives us something to talk about in terms of how fast players are (or aren't).
Table shows all first-round running backs since 2000, with 40 times. They're official combine times unless they're marked with an asterisk; those are either pro days or estimates. Last column shows the best fantasy rank (1 point for every 10 yards, 6 points for touchdowns) each player achieved in his career. Heights and weights are included; a back the size of Ezekiel Elliott running a 4.47 is more noteworthy than a smaller back doing the same. So for Barkley to run a 4.40 at 6 foot, 233 pounds is pretty remarkable.
| RUNNING BACK 40 TIMES, 1ST-ROUNDERS (2000-PRESENT) | ||||||
|---|---|---|---|---|---|---|
| Year | Pick | Player | Ht | Wt | 40 | FF Rk |
| 2008 | 24 | Chris Johnson, Tenn. | 5.11 | 203 | 4.24 | 1 |
| 2008 | 4 | Darren McFadden, Oak. | 6.01 | 211 | 4.33 | 6 |
| 2010 | 30 | Jahvid Best, Det. | 5.10 | 199 | 4.35 | 23 |
| 2010 | 9 | C.J. Spiller, Buff. | 5.11 | 196 | 4.37 | 7 |
| 2006 | 2 | Reggie Bush, N.O. | 5.11 | 201 | 4.37* | 10 |
| 2012 | 32 | David Wilson, NYG | 5.10 | 206 | 4.38 | 45 |
| 2004 | 30 | Kevin Jones, Det. | 6.00 | 227 | 4.38* | 21 |
| 2001 | 27 | Michael Bennett, Minn. | 5.09 | 207 | 4.38 | 17 |
| 2007 | 7 | Adrian Peterson, Minn. | 6.01 | 217 | 4.40 | 1 |
| 2006 | 30 | Joseph Addai, Ind. | 5.11 | 214 | 4.40 | 4 |
| 2008 | 23 | Rashard Mendenhall, Pitt. | 5.10 | 225 | 4.41 | 7 |
| 2001 | 23 | Deuce McAllister, N.O. | 6.01 | 222 | 4.41 | 6 |
| 2000 | 31 | Trung Canidate, St.L. | 5.11 | 193 | 4.41 | 35 |
| 2005 | 5 | Cadillac Williams, T.B. | 5.11 | 217 | 4.43 | 19 |
| 2005 | 2 | Ronnie Brown, Mia. | 6.00 | 233 | 4.43 | 23 |
| 2008 | 22 | Felix Jones, Dall. | 5.10 | 207 | 4.44 | 26 |
| 2010 | 12 | Ryan Mathews, S.D. | 6.00 | 218 | 4.45 | 8 |
| 2004 | 24 | Steven Jackson, St.L. | 6.01 | 241 | 4.45 | 3 |
| 2003 | 23 | Willis McGahee, Buff. | 6.00 | 223 | 4.45* | 8 |
| 2002 | 18 | T.J. Duckett, Atl. | 6.00 | 254 | 4.45* | 21 |
| 2000 | 7 | Thomas Jones, Ariz. | 5.10 | 216 | 4.45* | 5 |
| 2012 | 31 | Doug Martin, T.B. | 5.09 | 223 | 4.46 | 3 |
| 2009 | 27 | Donald Brown, Ind. | 5.10 | 210 | 4.46 | 35 |
| 2008 | 13 | Jonathan Stewart, Car. | 5.10 | 235 | 4.46 | 12 |
| 2007 | 12 | Marshawn Lynch, Buff. | 5.11 | 215 | 4.46 | 3 |
| 2001 | 5 | LaDainian Tomlinson, S.D. | 5.10 | 221 | 4.46 | 1 |
| 2016 | 4 | Ezekiel Elliott, Dall. | 6.00 | 225 | 4.47 | 2 |
| 2017 | 8 | Christian McCaffrey, Car. | 5.11 | 202 | 4.48 | 18 |
| 2012 | 3 | Trent Richardson, Clev. | 5.09 | 228 | 4.48* | 10 |
| 2006 | 21 | Laurence Maroney, N.E. | 6.00 | 217 | 4.48* | 25 |
| 2006 | 27 | DeAngelo Williams, Car. | 5.09 | 214 | 4.49* | 1 |
| 2009 | 12 | Knowshon Moreno, Den. | 5.11 | 217 | 4.50 | 5 |
| 2017 | 4 | Leonard Fournette, Jac. | 6.01 | 230 | 4.51 | 8 |
| 2015 | 10 | Todd Gurley, St.L. | 6.01 | 222 | 4.52* | 1 |
| 2015 | 15 | Melvin Gordon, S.D. | 6.01 | 215 | 4.52 | 8 |
| 2009 | 31 | Beanie Wells, Ariz. | 6.01 | 235 | 4.52 | 17 |
| 2004 | 26 | Chris Perry, Cin. | 6.00 | 224 | 4.55* | 46 |
| 2003 | 27 | Larry Johnson, K.C. | 6.01 | 228 | 4.55* | 2 |
| 2000 | 5 | Jamal Lewis, Balt. | 6.00 | 240 | 4.58* | 4 |
| 2000 | 19 | Shaun Alexander, Sea. | 6.00 | 218 | 4.58* | 1 |
| 2002 | 16 | William Green, Clev. | 6.00 | 221 | 4.60 | 27 |
| 2011 | 28 | Mark Ingram, N.O. | 5.09 | 215 | 4.62 | 6 |
| 2005 | 4 | Cedric Benson, Chi. | 5.10 | 222 | 4.62* | 15 |
| 2000 | 11 | Ron Dayne, NYG | 5.11 | 259 | 4.65* | 29 |
So of the six fastest 40 times among the first-rounders, five of those guys had at least one top-1o fantasy season (and the exception was Jahvid Best, who didn't lack for talent but durability). As the times get a lot slower, you have more players who never had a top-10 fantasy season: Green, Benson, Dayne.
But it's not the end-all and be-all, since plenty of guys with slower official or estimated 40s have been excellent fantasy performers: Larry Johnson, Jamal Lewis, Shaun Alexander. And then guys in the 4.50 area have gone either way.
Barkley is going to be a first-round pick, and he'll slot in right next to Adrian Peterson on this list. Appealing. The immortal Trung Canidate is also in that region, of course.
Bottom line: 40 times are what they are. Fast is nice. But plenty of faster backs have never done much in the NFL, and plenty of backs with slower times have gone on to be very nice fantasy players.