Memorizing chess openings by turning them into lists of numbers

In the last few months, I've been using a version of memchess.com that I rebuilt from its archive [1] in order to learn chess openings.

I am moderately happy with my results so far, but during this process I've learned a lot about how memory works, and about the various techniques that are used to improve it. However, it seems to me that none of these techniques, apart from the space repetition method, works well with chess.

Don't get me wrong: the space repetition methods is great, but I can't help wondering if I could not make it work even better. How could I use the method of Loci? How could I turn a chess move or position into an image that would be more vivid than a mere chess board which, to be honest, I can't really visualize very well? In other words : how can I "encode" a move in a way that has nothing to do with chess?

So called memory champions are amazingly good at memorizing long sequences of numbers, so the question is : how could I turn a sequence of chess moves into a sequence of numbers? If I could do that, all the experts methods to memorize numbers could be used seemlessly to memorize a chess opening repertoire.

Then I thought about this recent video someone made about the rarest chess move[2], and I started analysing my current repertoire (the one that used to be on memchess.com) to see how many chess moves it contains. To my suprise, it was just about five hundreds, which is much fewer than what I expected.

Here are the ten most common moves (half-moves, really) of my white repertoire, along with their number of occurrences:

    d4    13147
    Nf3   12848
    O-O   12562
    Nf6   12278
    e4    10430
    Nc3   10323
    d5     7540
    c5     7431
    e6     7276
    c4     7207

In total, there are 593 half-moves. That's a lot, but it's not something that should scare someone who's familiar with mnemonics.

So, here is what I think could work. A preliminary task would be to memorize the list of half-moves, in decreasing order of frequency. In the list above, for instance, d4 would be the first entry, thus the number 1, Nf3 would be 2, d5 would be 7 and so on. I think it's important to sort the list in decreasing order of frequency so the numbers to memorize are as small as possible, thus achieving some sort of compression. When this list is memorized, one just has to use common mnemonics techniques to memorize each opening lines, turning them into a list of numbers and memorizing them with the method of Loci, the major/Dominic system or something like that.

Thoughts?

1. https://news.ycombinator.com/item?id=39661497 2. https://news.ycombinator.com/item?id=40636883