Adrian Peterson or Arian Foster?

I'd take the trade. You probably can't go wrong with either guy, as everyone should have AP and Arian as they're top 2 fantasy runningbacks in the league right now (the order however is debatable). With that said, there are two main differences for the stretch run. Foster has the much better matchups for the Weeks 15 & 16 you are playing, plus Arian is on the better offense with the stronger QB. For the matchups, AP faces the the 3rd and 13th best run defenses in the NFL in Week 15 and 16, respectively. Arian on the other hand draws considerably easier opponents, the 22nd and 30th best run defenses in the NFL. Arian should also get more holes and spots to run as the Texans have a ping game to be reckoned with now that Andre Johnson is healthy again. Favre got hurt today and AP may have to deal with Tarvaris Jackson as his QB now.