Alphabet-based 2-card System

This idea is very simple, so I find it unlikely that I am the first to come up with it. Either way, I haven’t found any mentions of it on the forum, so I thought I would share this with everyone.

A 2-card system is usually thought of as having 52^2 = 2704 images, one for every pair of cards (more accurately, 52 * 51 = 2652 images since a card can never pair with itself).

However, from my (limited) understanding, the Shadow System accomplishes the benefits of a 2-card system with only 1352 images. This is done by allowing certain pairs to ‘share’ an image, so for example 6H/4H would have the same image as 6S/4S. These two images can be distinguished during recall by where they are placed in the memory palace. e.g. If they are placed at the same locus as the previous image, it would be 6H/4H, but if the image is placed at a new locus then the cards were 6S/4S.

My idea is to use a similar concept to the Shadow system, so that only 1352 images are necessary. To accomplish this, each card is assigned a letter from the English alphabet, A-Z (or any alphabet with >=26 letters). Note that in this case, each letter will belong to two different cards (this is explained further below).

Let’s say only the spades and hearts are assigned letters, so A-M are the ace-king of spades and N-Z are the ace-king of hearts. Each pair of cards is now a letter pair, so 6H AS would be SA, or a SodA. I find it easiest to find words that start/end with the two letters, but other conventions are also possible.

From here, we can expand the system to include clubs and diamonds: so A-M will apply to spades or clubs, and N-Z applies to hearts or diamonds.

Differentiating between the suits can be done similarly to the shadow system. However, this system would need two indicators, since each letter pair has four possible interpretations. For example, SA could stand for:

6 of hearts (S) and ace of spades (A)
6 of hearts (S) and ace of clubs (A)
6 of diamonds (S) and ace of spades (A)
6 of diamonds (S) and ace of clubs (A)

To remedy this, I propose that for the first letter of the pair, we do as is done in the shadow system, and use the location in the memory palace to determine if it’s in spades/hearts or clubs/diamonds. I haven’t found a suitable way to encode the second letter yet, but here are some ideas.

  • Similar to the Shadow System, use location: this time, whether the image is vertically high or low.
  • Define two images for each letter pair, and use the second letter to determine which image you will be using. If the second card is in (spades/hearts) then it could be a person, otherwise it would be an object. e.g. SA could be a person (SarA) or an object (SodA) depending on if A is the ace of spades or the ace of clubs.
  • Building off of the previous method, we could simply treat this as a standard PO system and choose objects associated with the person for the letter pair. However, it would be more difficult to find so many people to fit into a system.

Note that in the first option I mentioned, only 26^2 = 676 images are needed. In the other two, we have two images for each letter pair, so the total is 26^2 * 2 = 1352.

This system would have more freedom than other 2-card systems, since it only has 2 letters to determine the image rather than consonant-vowel-consonant. Also, the existence of similar letter pairs such as CK, KC, CQ would make this somewhat more difficult. There are also difficult letter pairs like XB and QN which may take more creativity to crack. For that reason, I would recommend using sounds for certain letters, so X could be the ‘SH’ sound, and Q could be something else like ‘CH’ or ‘ST’ in order to make it easier to find words.

Let me know if you have any feedback, or any suggestions for how to solve the problem of encoding each of the four possibilities for a letter pair! Do you think the Person/Object approach is good enough?

Edit: Added information on total number of images required for the system.

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