Anki 2.1.52 qt6 stats bug (Future due - Backlog)

If I open the deck stats, go to ‘Future due’ and enable Backlog, the graph displays a lot more backlog cards than there actually are

I am using Anki 2.1.52 qt6 on Windows 10
The problem happens for all decks, even with all addons disabled
It does not seem to occur on Anki 2.1.49 or Anki 2.1.51 qt6.

Example 1 (a deck with an actual backlog of about 40 days)

Anki 2.1.52 qt6

Anki 2.1.49

Anki 2.1.51 qt6

Example 2 (a deck I only started studying a few weeks ago)

Anki 2.1.52 qt6

Anki 2.1.49

Anki 2.1.51 qt6

Thanks for the report, a fix will be in the next build. In the mean time, adding -is:new to the search should fix it.


Another thing:
if Backlog is enabled, the Average is calculated on a period of time that, instead of starting from ‘day 0’, goes back to the beginning of the backlog.


  • in the graph below, with Backlog enabled, there is a total of 12862 reviews, with an average of 141 reviews/day (12862/91 ≈ 141).
  • in the second graph, there are only 5488 reviews, but an average of 177 reviews/day (5488/31 ≈ 177), higher than with Backlog enabled.

Since this also happens in Anki 2.1.49, I am not sure if it is a bug or an intended feature.
I would argue, though, that calculating the average this way is not very useful and is in fact a bit misleading.
It would be much more interesting if it was calculated starting from ‘day 0’, so that you would know how many card you will need to study daily to burn through your backlog and the upcoming reviews

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