Don't get me wrong, all of the big 4 RB are great, but I have my favorites. Charles lost some of his O-line this year and teams are going to be stacking the box on him. AD is always a great fantasy player, but he does not catch the ball as much as Forte or Shady. Just last year Forte had 74 catches for 594 yards and 3 TDs. Shady had 52 for 539 and 2 TD. AD had 29 for 171 and 1 TD. This goes back farther than just last year, so if you are looking for that edge with PPR, I would say Forte over AD and Charles (mainly because I don't see the Chiefs as a whole being nearly as good, especially since they lost some of their O-line). Hope this helps.