Reaching proficiency by the end of a players SO season sounds pretty good to me. Of course since you'll be running a FCP you will need to rely on younger players to play more minutes, so a team would take a hit on defense. At least in the beginning of the season.
I understand why you wouldn't want to give out your Player Value Rating equations on the forums, but I'm interested. I use a spreadsheet to calculate a modified
Player Efficiency Rating. It has to be modified, because the real equation requires info that this game doesn't provide (although maybe it is all calculable?). I use an equation that is easy enough to program into a spreadsheet which
I found in an old forum post.
I would think that comparing your player rating calculation to their PER would be a pretty good test for both equations.