Easiest → Hardest

1. Real Easy Days: https://github.com/open-spaced-repetition/fsrs4anki-helper/issues/429
   1. Simple solution: broaden the fuzz range
   2. Complex solution: dynamically reschedule
2. Real Load Balancer: https://github.com/open-spaced-repetition/fsrs4anki-helper/issues/474
   1. Need to store the average duration per review in card info to resolve performance issues
3. Handle Custom Interval: https://github.com/open-spaced-repetition/fsrs4anki/issues/675
   1. Should it be treated as a review? What’s the rating of this kind of review?
   2. Solution candidate: https://supermemopedia.com/wiki/Ctrl%2BJ_vs._Ctrl%2BShift%2BR
4. Consider Deadline: https://github.com/open-spaced-repetition/fsrs4anki-helper/issues/456
   1. How to maximize the total knowledge retention on the day of the deadline?
5. Automatic Preset Assigning**:** https://github.com/open-spaced-repetition/fsrs4anki/issues/709
   1. A clustering problem?
6. Improve Difficulty: https://github.com/open-spaced-repetition/fsrs4anki/issues/352
   1. Numerous ideas proved ineffective.
7. Short-term Memory Model: https://github.com/open-spaced-repetition/short-term-memory-research/issues/3
   1. Still In Research.
8. How related cards affect each other: https://github.com/orgs/open-spaced-repetition/discussions/28
   1. https://www.justinmath.com/individualized-spaced-repetition-in-hierarchical-knowledge-structures/
   2. https://arxiv.org/abs/2402.12291