I was thinking that perhaps it might be worth considering to have position experience be gained on more of a curve, so that while it continues to be as easy as it is now for (intelligent) players to learn a position, it may take them years to fully master it. As it is, most of my rookies have fully mastered their position a quarter of the way into the season. The difference would likely be so subtle as to be relatively negligible, but it'd be nice to still see savvy vets picking up a few new tricks along the way.