Comment by TheDong

My tip is to map the 1-4 difficulties as "wrong, or <60% confidence", "60-80% confidence, thought required", "90%+ confidence, thought required", and "90%+ confidence, no serious thought".

Depending on what you're learning, you might vary those. For language learning, that works well imo.

Also, make sure to switch to FSRS. The old algorithm defaulted to "again" resetting a card to 0, while "again" in FSRS does show it again, but doesn't reset it back to being effectively new.

If you want to understand the algorithm, read this: https://github.com/open-spaced-repetition/fsrs4anki/wiki/ABC...