The combine has posted the official 40 times for RBs which confirms that Georgia’s Keith Marshall had the fastest time at a very quick 4.31. Marshall, in fact, was the only back to break the 4.4 mark as San Jose State’s Tyler Ervin had the next best time at 4.41. Among the top backs, Ohio State’s Zeke Elliott was credited with an official clocking of 4.47 which is not at all bad for a 225-pound guy, although he likely was hoping for something close a tenth faster. Meanwhile, Alabama’s Derrick Henry finished with a 4.54 clocking, again which isn’t bad for a 247-pound runner. NFL teams, though, will have to chew on the times of Alex Collins of Arkansas (4.59) and Louisiana Tech’s Kenneth Dixon (4.58) who are generally thought to be the 3-4 backs this year as neither time was that of a guy who is going to break off many big runs on his own.