What rules does the shuffle feature use to generate a sequence?

I’ve noticed that the shuffle feature on the clip and clip+ don’t seem to be purely random. Can anyone confirm or add to these?

  1. Some songs seem to be chosen more than others. Does it go by the ratings you have given them?

  2. It seems like it will start repeating some songs before it has played other songs. Is that normal? Does each song have an even chance, even if it’s been played before, or is it supposed to play all the songs just once in some random order?

  3. It tends to play two or three songs by the same artist back to back. I  can’t tell whether it’s going by artist or album. If they have made it that way deliberately, I think it’s a good idea. It suits my listening style.

One rule: the longest straw wins!

My experience with the regular Clip (not the plus) is that you have to tag the files with track numbers. (MP3tag works nicely.) It’s a pain but I think that’s what one has to do. If you’ve already tagged with track numbers, I don’t know what to tell you. 

I have an old Rio which will randomize based on filenames, but I think the Clip needs track numbers to “shuffle” play. The tendency to repeat tracks before playing all was a problem with the previous generation of Clip too, but I think it was solved with one of the late firmware releases.