Nah, I tried that already. If you don't touch the C potentials, it'll come back to haunt you. A lot of the C's become B's, some even A's after a few years in the minors. That's how my franchise got flooded with B's and A's.
At first I only edited B's and A's but still noticed there were too many C's improving their potentials.
You have to edit ALL of the pitching prospects that are drafted. Maybe you can leave those D's alone, but as far as C's go, I always make sure to drop them to like a 68 potential.
I read an analysis online about the rate at which 1st round draft choices make it to the show. About half of them make it to the majors at some point in their careers. As soon as you get out of the first round, your chances at playing in the majors dramatically drop. This conclusion was drawn from analyzing the 2007 through 2012 drafts so it is a modern day study.
So, let's say 25 SP's are taken, I think only 7 should be good enough to where they MIGHT progress to be MLB worthy. The other guys should become career minor leaguers or local car salesmen. D's across the board.
The fear is that if we leave too many pitchers as C's, they might get the potential boost to B and become talented enough for an MLB rotation.
I don't even know anymore, guys. I'm just spitballing. It's pathetic the gaming community has to come up with ideas to improve the simulation because the developers are too lazy to simulate franchise mode and test out the progression.