[michaelcampbell]

> Every card remembers every rating you give it, as well as the time / date. This allows for Anki to solve for a 'forgetting curve', and predict when different cards have a chance to be forgotten.

True to a point; every card has its ratings, but the "forgetting curve" algo of FSRS is only tuned to the deck (or "option set") that the card is in, not per card.

[dragontamer]

The entire FSRS parameter set (~20+ parameters, depending on FSRS version) is per deck.

Each card is tuned to... 2 parameters IIRC? f(Difficulty, Stability, Time) == Retrievability. Time is just time so its not really a parameter, but Difficulty and Stability is solved on a per-card basis.