I don't know why we get these unintelligent posts (I didn't think this thread was about whether or not Bell was a good start in a flex position...) when I think it's been said over the course of the top couple:
1) he's in the wrong system to be a #1
2) he can't seem to carry the ball 20+ a game
I think it's clear that yes, Tatum is very talented... however he has issues hanging onto the ball and he is clearly in the wrong system. The Denver offense is designed for a back like Terrell Davis to have success... which is exciting news for Mike Bell who has been compared to T.D. all of camp. He even declined the #30 saying he doesn't deserve it.
Anyways, Tatum is an outside runner, he can't run inside. In fact, if you read the Bronco's training camp thread you'll see that Shanny actually scolded Tatum for running up the middle rather than cut outside. He clearly wants to use Tatum just as he did last year- a change of pace back that'll get 10 carries a game, cut it outside, and hopefully average 6-7 yards per carry. I think Tatum is most effective in this role and he should be happy for it. He's as productive as a 10 touch a game back in Denver as he would be as a #1 starter on any other team in the league. Yeah. I said it.
Unless Mike Bell completely self destructs, you'll definately see the same thing you saw last year with Anderson and Tatum. Remember, last year everyone said that Tatum would take the starting role from Anderson after it was given to him in camp. Hell, I even said that and I think I drafted Tatum... Anderson never let go of that starting job and both RBs were effective