Too old school and too effective.

FSRS just works, even without a GPU so it's not the cool kind of AI / machine learning these days.

No joke though: the FSRS model is marvelous, and Anki remains one of the best free + open source implementations around.

I've been learning German recently and Anki (in FSRS mode) is one of the most important learning tools I have. No joke.

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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.

There is furthermore the machine learning / stochastic descent algorithm to better fit the assumed forgetting curves to your historical performance. This is the FSRS Optimize parameters button in the settings panel.