I just updated to 24.11, and after reoptimizing my FSRS params, a huge number of my cards are marked as >90% difficulty:
Previously, my difficulty curve looked more like a broad normal distribution centered around 60% or so. I guess I just wanted to make sure this radical change isn’t a bug or an indication that I’m doing something wrong!
I took a screenshot of my FSRS params and eval if that’s useful as well.
It’s not a bug. It just shows that FSRS decided not to distinguish these piled cards’ difficulty. Difficulty is just a relative variable in FSRS, unlike SM-2’s ease factor.
Technically speaking, w[8] determines the overall difficulty of the set, while D only differentiates the relative difficulty between different cards.
Also difficulty is not integer, so there can be cards with D ~ 0.996 and 0.997 sorted in the Browser, even though it shows 100% for both.
