Stats and backups

[Xtra]

Okay, I know that I can pretty much ignore the OVR stat, except to know where I can start looking.

But what I don't know is what stats to look at for most positions, or if their overall increasing if I move them to a similar position (outside linebacker to middle linebacker, for example) means anything.

Also, the game seems to fill all my backup spots with the players that have the highest OVR that are not starters, and I don't have enough players to adequately fill all the slots, so some of my backups are backing up multiple positions. Is this okay to do, and how do they work it out in preseason games?