Now that we're halfway through the fantasy football season, let's take a look at this year's crop of rookie running backs.  Here are my rankings:
 
Four Stars:
 
Chris Johnson, Ten - Johnson has been the workhorse back and offensive star for the Titans this season, with 15+ carries every game.  Most people (including myself) saw Johnson as merely the change-of-pace back to a leading LenDale White, but that has been completely backwards. As a rookie he is likely to tire out towards the end of the season though so look for the Titans to lessen his load, especially if they've clinched a playoff spot early.
 
Matt Forte, Chi - Everybody knew he was starting (hopefully you didn't buy into that Kevin Jones gimmick) but few people expected this.  Forte is 8th in the league in rushing with 515 yards and should continue on to a 1000 yard rushing season.  His average of 3.5 yds/carry is a concern, but as long as the Bears keep giving him the ball 20+ times (as they have 5 of 7 games so far) it won't matter too much.
 

Three Stars
 
Steve Slaton, Hou - I'm surprised I didn't think more of him in the preseason when I knew -- I knew! -- the Texans didn't have anybody to start at RB.  I guess I just assumed they would make a bad decision and go with Ahman Green.  Well, 423 rushing yards and 3 TDs later, Slaton is a regular fantasy starter -- but here comes Ahman Green.  Maybe I was right after all.  It's hard to see how this season will end up for Slaton.
 
Jonathan Stewart, Car - He's been sharing time with DeAngelo Williams (as expected) but has been grabbing the goal line touchdowns (as expected).  So far, about what I expected.  That doesn't make it any easier to use him in fantasy though, where the Panthers' will-they/won't they RB system drives you nuts.  Carolina has won every game where Stewart has 10+ carries, and has lost every game where he has fewer than ten carries, so Stewart owners hope the Panthers catch on to that trend damn soon.