Percent Rushes Gaining 16+ Yards
The basic idea: Steven Jackson was an outstanding running back and leader for the Rams, but the team would trade some of his power and determination for longer gains. Jackson, though still effective at age 30, wasn't going to be gaining in the speed department. And so the Rams are moving forward with younger backs.
NFL teams often define explosive running plays as those covering at least 16 yards. The chart shows Jackson producing such runs on 3.9 percent of his carries while with the Rams, including a career-low 2.7 percent last season. I've included for reference annual and career percentages for NFC West backs Marshawn Lynch and Frank Gore.
Jackson had seven such carries in 2012. Backup Daryl Richardson had five on 98 carries, or 5.1 percent. Isaiah Pead had one on 19 carries. Different backs face different opportunities based on blocking and to what degree defenses must respect other potential threats on the field. Jackson hasn't had much to work with on those fronts over the years.
Karraker, Farr and I pick up the discussion here.