There are actually several questions nested in this thread, so I’ll try to present them in some logical order.
I’ve periodically seen discussions about potential 10,000-image systems, but I’ve always wondered if it would even be possible to preserve image uniqueness with a list so large. I know that there are also semantic elements to memories, but I’ve always considered visual uniqueness to be very important. Having recently finished completing a 2704-image list, the idea of creating a 10,000-image list while retaining uniqueness seems absolutely impossible. In consequence, it seems like the semantic elements would have to play a larger role, which I suspect would result in more time spent per image.
A 10,000-image system would allow for 33% greater efficiency (compared to a 3-digit system) for decimals and a 20% greater efficiency for binary (4 segments, each 0 - 7, 000-000-000-000 - 111-111-111-111), but due to the loss of uniqueness, I expect that the actual benefit would be less. Moreover, for cards–where there is no benefit–I expect that times would actually be a little worse (due to the reasons stated earlier).
I’m curious about what others have to say. Is it actually possible to retain a reasonable level of visual uniqueness with a 10,000-image system? Are the semantic elements strong enough to make this a non-issue? Would you expect there to be a slower rate (images per time)?
Most importantly, is there anybody who actually uses a 10,000-image system? If so, what are his/her times like?
Notes: I think the card problem could be fixed by carefully constructing the card subset with a strict uniqueness condition. There would be no similar-looking images within this subset, so there would be no possible confusion when memorizing cards.
The phonetics underlying a system like this I think would work best with a category-based approach. From experience, though, a category-based approach yields inanimate objects almost exclusively (Or is it just me?), so the list could easily have a disproportionately high number of inanimate objects, making interactions within loci more difficult.