Anyone know who makes the ratings for the LS cards (I remember Ramone/Luis mentioning it was a different company during a live stream) or how they do it?

I've been trying for months to come up with equations to make my own roster that would be more realistic/better for franchise/simulation. I think I've got pitchers' per 9 stats and stamina nailed down, but I cant figure out how to do pitch control/break, hitting stats, or fielding stats.