It wasn't difficult to determine what the Los Angeles Rams offense lacked last season. While reports after the season ended revealed that quarterback Matthew Stafford suffered a serious rib injury, that was only one problem. The Rams running backs were not fast, and the Rams suffered from having hte fewest explosive running plays in the entire NFL.
That's correct. In the category of runs that gained 20+ yards, the team fell dead last in the NFL, recording just two running plays of that type. The running backs are well aware of that deficit and are working hard to remedy the matter.