When the LA Rams were operating at their greatest potential in 2018, it was in part because of having the NFL’s most efficient rushing attack by a wide margin. With Todd Gurley as a support system in place for Jared Goff and company, the Rams finished that season ranked first in rushing DVOA by a massive margin: 20.6% for LA, 9.5% for second-place Carolina Panthers.
Even if those percentages don’t mean anything to you (and they probably shouldn’t, so don’t fret), the gap of being “twice as efficient” from 10% to 20% is a fair estimation.