Football Outsiders has a post up today on the success of teams running in one-back and two-back offenses. The Texans ranked first in DVOA in both offenses, which was not a total shock, considering how well they did last season in the running game.
However, Houston also did it out of a two-back set with Vonta Leach about 65 percent of the time. That was about 12 percent higher than league average last season. The only teams who featured two backs more often were Jacksonville, Green Bay, Dallas, Oakland and Miami. Baltimore, the team who signed Leach to that big deal earlier this week, ran two backs the same percentage of the time as Houston.
With Arian Foster, Houston will likely be good running the ball out of either set again this year, but you see the reason why signing a guy like Lawrence Vickers was important. James Casey may make a successful transition to fullback, but with the frequency that Houston runs that set, it's nice to have another option like Vickers in the offense.
Incidentally, Cleveland (where Vickers spent last season) had the seventh-highest DVOA in two-back sets with Vickers and a much, much lower percentage on one-back sets. That suggests Vickers is not just a warm body filling in for Leach. Cleveland also used the two-back set about as often as Houston, so Vickers shouldn't be overwhelmed with his new workload.