In my opinion, the only backups worth grabbing are guys that have a shot at getting 20-30 carries a game if the RB1 goes down. For instance, Morris (SEA), Turner (SD) & Jacobs (NYG) all look like they'd be plugged in and worked to death and produce nice numbers.
The ones I avoid is where even if the main guy went down, there's no 20-30 carry p/g replacement: Betts/Duckett (WAS), Henry/White (TEN), Morency/Dayne/Lundy (HOU) anybody in the NYJ backfield, etc.
And taking the backup in a non-productive offense just seems silly beyond that (BUF, GB, SF) to waste a roster spot rooting for an injury in a sitation that's not great to begin with.
I think there's only 3-5 true backup RBs worth taking any kind of flyer on. That's not including guys in 2-man RBBC situations (Bush/Deuce, Jones/Benson, etc.)
I'd sooner make sneaky goal-line vulture plays, possible breakthrough WRs, looking a week ahead for DEFs with great matchups and backup/handcuffed QBs like Leinart, Griese, Holcomb if you're in a deep league.
That's my two cents. Good luck on Sunday/Monday.
... in my opinion, of course - but that should always go without saying.
www.bigfellas.net (home of the golf rap "On The Green")