Quote Originally Posted by Sakasa View Post
Are the success rates shared between stats so I can risk a cheaper materia Sks to increase my success rate high enough to try the more expensive DET?
The stats are independent of each other.
For each tier of materia, around half of the required materia will have a 100% success rate before it slowly drops off.

Being on Tier IV for one stat have no effect on Tier I of another stat.