Thanks for the reply on that one. As long as the progression system allows for rookies to get better on the bench to a certain extent (maybe first three years) then I'm on board with your optimism. If people don't always hit their potential, then that would make the definition of "potential" a lot more subjective and I wouldn't mind seeing the grade at all...
..though that would mean a C/D/F grader would have to be able to exceed their potential, and that's something I used to argue against very strongly because it leads to people pumping up their player's stats with unrealistic on field stats (I believe certain players should never be able to exceed their physical potential, because that's how humanity works, but I'm not derailing this thread to open up THAT can of worms
)