Which RB's should I start this weekend in fantasy football (playoff game!)?

I would start Hightower for a few reasons. First, Detroit's run defense is easily the worst out of the four. I could probably rush for 100 yards against them and I haven't played football in years. Second, he gets more carries than the other three backs do. Bradshaw splits time with Brandon Jacobs and only ends up with 8-12 rushes per game. Bell splits time with Pierre Thomas and Lynch is pretty much a bust this year. Lastly, Detroit is competing for the #1 pick in the draft, so don't expect them to compete with a playoff team like the Cards.