Two officials in offensive backfield?

[jTheUmp]

Originally Posted by Sturno

One would assume the C would have O-line responsibilities and help cover offensive backfield action freeing up the R to keep his focus on QB responsibilities.

Basically correct.. although I'm not sure of the exact mechanics and coverages, I think they're primarily responsible for the opposite tackle.

I haven't seen enough of those mechanics, I'm curious where the C is positioned for scrimmage and free kick situations.

On free kicks, C starts out behind the kicker (where the Umpire used to line up in 6-man).

On punts, C's lined up opposite the R, just like any regular scrimmage play, only deeper. On Field Goals and Trys, I've seen a couple of variations: a) opposite the R as usual, or b) once I saw them run three officials (C, U, S) on the defensive side of the ball as a "triple umpire" formation.