I’ve been paying a little attention to the question about the success rate of a trace and your spell casting performance.
The guide here at:
- The only thing that determines whether a Spell affects your Foundable return rate is the color of the Spell bar
- If the Spell bar is all the same color , then your Spell cast level will have no impact on your Foundable return chance
However, some research reported in reddit seems to suggest that the success rate does actually vary within a same-color segment–but this is not tied to the “fair/good/great/masterful” breakpoints:
So the way you figure out what your actual success chance for a trace is where your white arrow ends up on the cast bar after you finish your trace.
The distribution of percent chances is linear across the cast bar. The distribution of percent chances across the bar directly matches the scaling of the threat wheel.
The post also includes a link to a detailed infographic about the threat wheel.
Of course, there’s no proof one way or the other, but it seems like the reddit folks have put a lot of study into this.