What running backs to start?

We start 2 RBs, and i have J Addai, B Westbrook, M Forte, and J Lewis. 1 point for every 10 rushing yards and 10 ping yards and 3 points per 5 receptions and 2 points per 5 rushes. I'm leaning towards Westbrook and Addai because Forte won't do anything against the stout Pitt D that doesn't allow 100 yard rushers. What do you think?