Do players gain position experience based on the position they are listed at on the roster page or based on where they are in my depth chart? Or both?

For example, if I put a WLB starting at WLB and as a backup at SLB and MLB will he gain experience at all 3 or just at WLB?

The get most experience from where they are assigned (not the depth chart, but their actual position assignment - because that is what they are focusing on during practice) but they also gain experience for every play they are on the field, whether that is their assigned position or not. The in-game experience will not overcome their position assignment, however, so it is always best to keep them assigned at the position you intend to play them the most.

thanks

Thanks JDB, that's what I was thinking but wanted to make sure.