[CrazedZooChimp]

"We talk often about the demands of learning the playbook, but that's usually for quarterbacks."

Not true at all as explained beautifully on another site by a players parent.  Said player is not a QB.

Name a very good Running back who switched to RB from WR after age 21?  Pro or College.

Does Percy Harvin count?  I'm not sure when or if he actually really switched, but he basically plays both positions and for his junior year Meyer officially listed him as a RB instead of a WR.  In the NFL I think he's sort of gone back and forth between the two positions.

[CrazedZooChimp]

"We talk often about the demands of learning the playbook, but that's usually for quarterbacks."

Not true at all as explained beautifully on another site by a players parent.  Said player is not a QB.

Name a very good Running back who switched to RB from WR after age 21?  Pro or College.

Does Percy Harvin count?  I'm not sure when or if he actually really switched, but he basically plays both positions and for his junior year Meyer officially listed him as a RB instead of a WR.  In the NFL I think he's sort of gone back and forth between the two positions.