They have said there is a way (or ways) to generate more but would not specify. Players have to be active and have an OVR under 60 (I believe that's the #). How much of it is random and how much driven by whatever their secret factor is, we don't know. It would make sense that it involves coaching somehow, and if so that would explain a hitter/pitcher split. A quick look at about 20 seasons across four worlds shows P/H splits ranging from 50-50 to 75-25 or so. In general more pitchers get it, which makes sense since most RP will have low OVR while for hitters that will tend to apply to C/1B/DH. If anyone has figured out the key ingredient, he has not shared it.