Thanks! It's determined via the FSRS algorithm. It starts out with the average retention curve for flashcards, but then adjusts to you as it learns your pattern

Thanks! It's determined via the FSRS algorithm. It starts out with the average retention curve for flashcards, but then adjusts to you as it learns your patterns. In the future, as I have more data, the initial curve can be tuned for piano specifically (since muscle memory degrades differently than plain text).