How does personalized scheduling work in Tomaru?

Personalized scheduling in Tomaru fits the 21 parameters of the open-source FSRS-6 algorithm directly to your review history. You start the process in your settings, and our servers run the fitting using the official FSRS optimizer—the exact implementation used by Anki. The resulting parameters are then applied automatically across every device and list.

What is personalized scheduling in Tomaru?

Personalized scheduling is the process of fitting the FSRS-6 algorithm's 21 memory parameters directly to your personal review history. Out of the box, Tomaru starts with default parameters calculated from a population average across many learners.

Once you accumulate enough study history, Tomaru retrains these 21 parameters using your personal review log, adjusting card intervals to match how fast or slow you actually forget words.

How does Tomaru calculate and apply your personal parameters?

The algorithm uses a single source of raw data: your review history log. Every time you rate a card using Forgot, Fuzzy, Clear, or Know it, Tomaru logs the rating and the exact time elapsed since your last review.

• Your review log records ratings and review intervals over time.
• The official FSRS optimizer processes your log on Tomaru's servers.
• 21 personalized parameters are generated and applied to your account automatically.

Once you are eligible, you start the optimization process from your settings. The retraining run executes on Tomaru's servers using the official FSRS optimizer—the exact same optimizer implementation used by Anki. Once calculated, your new parameter set applies automatically across every list and platform with nothing to copy, paste, or configure.

What is the eligibility threshold for parameter optimization?

Optimization becomes available after you accumulate approximately 1,000 eligible reviews. To ensure an accurate statistical model, Tomaru only counts reviews that occur at least 24 hours after the previous review of that card. Same-day repeats are excluded because short-term repetitions provide no information about long-term memory durability.

Below this threshold, fitting 21 parameters generates mathematical noise rather than a reliable memory model. Standard population defaults protect your schedule until sufficient data exists.

How do parameters differ from target retention?

Target retention and personalized parameters control completely different aspects of your schedule:

Changing your target retention adjusts your review frequency goal, but it does not alter the underlying model of how your memory behaves.

What changes will you notice in your daily reviews?

After optimization, review intervals shift away from generic defaults to reflect your personal recall strengths:

• Words you consistently recognize easily receive longer interval extensions, saving review time.
• Words you struggle to retain appear more frequently, preventing silent lapses.
• Future review queues smooth out based on your actual answering patterns rather than generalized population trends.

Can you edit individual parameters by hand?

No. Tomaru provides controls to start an optimization run or reset your account to default parameters, but it does not support manual editing of individual numbers. In practice, hand-adjusting 21 interconnected statistical variables without running a mathematical optimizer almost always yields worse results than population defaults.

To learn more about spaced repetition mechanics, read our guide on how spaced repetition works or check our overview of understanding your stats.

Related questions

How do I re-run optimization as I accumulate more reviews?

Whenever you have built up substantial new review history, you can open your settings and start optimization again. The server will re-fit all 21 parameters against your expanded log and apply the updated profile automatically.

Can I reset my parameters back to population defaults?

Yes. Account settings includes a control that restores your FSRS-6 schedule to the default population parameters at any time.

Will personal parameter optimization change the content of my cards?

No. Optimization updates only the scheduling math used to calculate review dates. It does not alter your word lists, card notes, or example sentences.

Do my custom parameters apply when I review cards on the web?

Yes. Your 21 personalized parameters are stored at the account level and apply identically whether you study on iOS, Android, or a web browser.