Mark Ingram ran a 4.62 in the 40-yard dash at the NFL Combine, which is considered to be on the slow side of average. In fact, the average 40-time for a RB since 2005 is 4.56, and that’s from a sample size of 163 RBs over six years.

Seven of the top eight rushers in the NFL — Chris Johnson (4.24), Jamaal Charles (4.38), Adrian Peterson (4.40), Maurice Jones-Drew (4.39), Michael Turner (4.49), Steven Jackson (4.45), Rashard Mendenhall (4.41) — ran a sub-4.5 in the 40-yard-dash.

There was one notable exception, and it was the top rusher of 2010, Arian Foster. He reportedly ran a 4.69 at his pro day, which just goes to show it doesn’t take elite speed to rack up yards.

Still, with so many of the top rushers with good to excellent speed, isn’t it worrisome for a team thinking about drafting Ingram? I posed this very question to our NFL guru, Anthony Stalter, who currently believes Ingram will go #15 to the Dolphins, and here is what he said:

There are a lot of fans and draft pundits who get too caught up in 40-yard dash times. When I watched Ingram last year, I saw a physical back but one that has great short-area quickness when he went through holes. It’s true, he doesn’t have great top-end speed and he’ll never be a back that can rely on straight-line speed (which is what the 40-yard dash measures). That said, Ingram is a very solid prospect.

I think one of the most overrated factors when sizing up a running back prospect is speed, with vision being the most underrated attribute. When I watch Ingram play, he reminds me of Emmitt Smith. The former Cowboy didn’t have great straight-line speed like Chris Johnson or Adrian Peterson, but he was a natural runner with tremendous vision, instinct and balance. I’m certainly not suggesting that Ingram is the next Emmitt, but he bears a resemblance to Smith when he runs.

That said, as John has pointed out, speed kills and the proof is in the pudding. When all of the elite running backs in the league are running in the 4.3s or 4.4s (or in CJ’s case, a freakish 4.2), it makes you wonder whether or not Ingram can be an elite back in the NFL. Then again, I haven’t heard one analyst deem him an elite prospect, so it’s all relative. It would be great if every top 15 pick were elite, but the draft remains the ultimate crapshoot. If the Dolphins were to take him at No. 15 and he wound up being a solid feature back for the next 6-8 seasons, went to 1-2 Pro Bowls but was never considered an elite player, wouldn’t their selection of him be considered successful?

After running a 4.62 forty at the combine, there’s a good chance that Ingram could drop into the bottom half of the first round. I still like him at No. 15 to Miami, but some teams are overly reliant on the forty so I could see him potentially falling come April. It would be too bad too, because I think he’s a nice overall player who has worked hard to shed some weight in the offseason.

Foster is the exception that proves the rule: Speed kills. It’s great that the undrafted Foster landed in a good situation in Houston and made the most of it. But Ingram is widely regarded as the top prospect in a weak RB draft, and in all likelihood will be a first round pick. If the Dolphins are drafting him in the middle of the first, isn’t it their expectation that he’ll be elite? And what are his chances of becoming elite without top-end speed?