@gyanamathsir Its a 2-card-per-element system, invented by @LociInTheSky, that uses Major System phonetics to create the words/images. There are specific sounds generated by the value of the number cards, the suit combinations, and the position of specific court cards within the pair.
The original version of the system was dubbed the “Shadow System” because each image had an opposing “shadow image” to differentiate red and black pairs. That approach has generally been replaced by making the system a true “2-block” one where each image corresponds to two card pairs and they are differentiated by the position they are assigned at a loci when memorizing.
Using the system requires making 1352 associations (one of every possible pair combination). While the learning curve is pretty steep, the advantage is that it allows the user to memorize a full deck using only 26 elements, and once the phonetics are learned, the associated word can literally be “read” from the card pair itself.
If you search for the tag: shadow-system you’ll find many threads discussing it.
Here’s the original thread outlining Lance’s initial system:
Here’s a couple I’ve posted with links to summary documents, an anki template deck, and a few info/worksheets.
I’m in the process of documenting my efforts to learn it and use it to memorize a deck in under one minute. I consider myself a novice when it comes to speed memorizing and took it on as a personal challenge. So far it has been really fun to learn and my memorizing time is under 1:40. My goal is to break one minute by the end of the year. That training journal is here, if you want a long guided tour from someone learning the system for the first time: