Comment by ralferoo

I'm not ready to share a link to my actual implementation yet, but I've been working on an SRS system for Chinese and been using it as my daily driver for about 3-4 years now, after previously using Anki and getting frustrated with how reviews pile up after a couple of days off.

I've done lots of tweaking to the algorithm over the years to make it feel like I'm less surprised by the scheduling, and less like a slave to it. One very stark difference between mine and Anki is that I have a large number of "overdue" cards, but the system still prioritises when to show me the overdue cards with quite a few different metrics based on how overdue it is, how new it is, how long the current interval is, etc. So, like Anki, I still just double the interval for correct cards, but for incorrect cards, the reviews are repeated same day until they're correct, and then the interval is reduced a lot more than Anki. So, the cards then become overdue sooner, but because the scheduling of overdue cards is better, they get pushed later if your overdue queue is too large, and sooner if you've not got anything more useful to review.

FWIW, my typical session is 40 minutes per day during my daily lunchtime walk, and I'll get through about 150 cards in that time. If I'm on a long train journey, I'll often clear out double that or more, but the disaster situation of being on holiday for a month might leave the queue with a couple of thousand extra cards, but they never seem unmanageable. Even after a 2 month break when I was travelling last year, and only doing reviews on flights and trains, I'd definitely forgotten some words from not reviewing at the appropriate time, but the percentage of totally forgotten cards felt better than I used to experience after just missing a few days with Anki.

One thing the article mentions that I don't massively concern myself with is desired retention. I'm not sure I'd want to express it as a target percentage, but I've definitely been thinking about how I want to change things to deprioritise stubborn words without just suspending them or deleting them. I definitely find that having them keep showing up, so I might see a pattern of them wrong twice each day before finally getting them right, after a few days of that they do usually suddenly stick for good. But sometimes I look at the word and think I don't really care if I remember it or not.