The Baltimore Ravens backfield is considered the third-best in the NFL, according to the story, Ranking The NFL's Deepest Backfields. The combination of Ray Rice and Bernard Pierce rate behind the San Francisco 49er's and Seattle Seahawks in the aforementioned link above.
Here is what is said about the Baltimore rushing attack:
Like Gore and Lynch, Rice is another workhorse back who has carried the load for years. We tabbed Pierce to make the leap this season and move into more of a split-duty role with Rice. Pierce's workload increased as last season wore on, and the Ravens leaned hard on his downhill, tackle-shedding style in the playoffs. Rice is still the main dish, but Pierce makes this ground game a versatile beast.