dfan says

Mnemosyne is a spaced repetition program for aiding memorization; see my first and second posts for more information on the program and how I use it.

I guess it is high time for another update; when digging out the above posts I was startled to see that they’re from four years ago. I’ll mostly discuss my experience using it for chess, since that’s what the majority of my 8000 cards are.

I’ll skip to the exciting conclusion first: since starting to use Mnemosyne for chess knowledge, my USCF rating has risen from a pretty stable 1800 over fifteen years of on-and-off playing to over 2000. That may not look that impressive, but the chess rating system is effectively logarithmic; the difference of 200 points means that new me would score about 75% against old me, so that’s a pretty big jump, especially for a middle-aged person with a previously stable rating like me. Of course, correlation does not imply causation, and there’s always a bunch of noise involved in chess results, but I’ve now played enough games in a row (around 60) with a performance rating of over 2000 that I feel comfortable assuming that I have actually improved.

The majority of my chess flashcards are opening positions. Here’s an example:

Sometimes the answer includes some explanatory text to help me remember why the move is good.

Having openings memorized has had the most obvious effect on my play of any of my flashcard categories. Although rote memorization of opening lines is generally frowned upon, I’ve noticed the following benefits:

• Most obviously, I have internalized thousands of good opening moves, so I am less likely to make bad moves in the opening, or spend lots of time figuring out good moves on the fly.
• I am often able to gain time on my opponents in the opening, as they are “out of book” and thinking on their own before I am. Even if they find good moves, they use up valuable time on them.
• I am now able to play very sharp (tactical and tricky) openings because I’m confident that I can navigate their waters. This allows me to play much more interesting and dynamic chess than I previously felt capable of doing.

There are drawbacks as well: my memory can fail me in a complicated line, or my memorization can run out too early in a tricky position if I was careless entering the line, or I can enter a position by rote that I haven’t spent much time thinking about strategically and have to wing it. But overall it is a clear benefit.

Most of my other chess flashcards come from exercises in books. I started with theoretical endgame positions, which require concrete fact-based knowledge in the same way that openings do. (I used Bernd Rosen’s Chess Endgame Training for this.) But then I decided that since chess is largely about pattern recognition (so that your eye is drawn to promising moves), I could try shoving tons of patterns in my brain and hopefully they’d stick around subconsciously influencing my thought as I played. For this purpose I’ve used exercises from the following books:

• Yusupov, Build Up Your Chess et al
• Ivashchenko, Chess School
• Cheng, Practical Chess Exercises
• Hellsten, Mastering Chess Strategy

It’s hard for me to assess how these cards have affected my play. I don’t think I can recall any particular situation in a tournament game in which I consciously remembered a particular card (even an endgame one), prompting me to notice a specific good move that was otherwise eluding me. But they certainly haven’t hurt, and the effect I was hoping for was more of a subconscious one anyway, and as I said my rating has gone up along with this regimen, so I’m continuing to proceed with the assumption that they’re helping my play.

How much time does this all take? On any given day I have to review about 60 to 100 cards, which takes me probably between 10 and 30 minutes (opening positions can take a while, since when a card comes up I first play through the variation on a virtual chessboard), though I usually don’t review them all at once. Making cards can be a little tedious (I don’t want to do the calculation to figure out how much time I’ve spent making all 8000!), but it seems a small price to pay to prevent the knowledge I’ve just acquired from leaking out.

The other topic that spaced repetition has been the most useful for is math. I enjoy reading math and physics textbooks but my retention is poor, so I’m constantly starting over. This causes even more problems because I already half-know the early material in the book, so I skim it, which means that once again I’m not really internalizing it. Memorizing formulas and concepts means that I don’t have to start from square one every time.

Other categories in my deck:

• Esperanto vocabulary: I still haven’t picked this back up since the last time I mentioned it, but it’s nice to know that because I review a few cards a day, it’s still in shape if I ever pick it back up.
• Go problems and joseki: I’m not sure how much this has really helped me, since I haven’t played Go very actively in the last few years, but it’ll be interesting to see if I have less rust than usual the next time I pick up the game.
• Japanese hiragana and katakana: I clearly still haven’t still internalized these, since once I do well enough on one of them that I go a few months without seeing it again, I tend to forget it the next time. I’m sure this is due to the fact that I’m not doing anything with this knowledge, so I never have any context other than the flashcards.
• Cyrillic: so I can read proper nouns on Russian chess websites. Definitely a success.
• Keyboard shortcuts for Sibelius (music scoring program): mixed success. A lot of shortcuts are very abstract like Ctrl-Shift-Down, so they’re pretty hard to memorize. I think I need to learn these more with my fingers than with my eyes and brain.

Overall, using spaced repetition has been a tremendous benefit to me. To take the chess example: even if I hadn’t seemed to have improved as a result, knowing that all the studying I do is not just pouring water into a leaky bucket (as it seemed to be for the previous 15 years), but instead is permanent in some sense, has made me immensely more motivated to learn. The same is true for other subjects like math. If any of the above discussion makes you jealous, I highly recommend you give it a try.