Originally posted by BruceBanner When you say 'shots deemed most interesting' does that mean the ones that get the most views or favorites?
The algorithm is only partially understood and is changed from time to time. "Interesting" is a combination of known pleasing photographic elements combined with initial popularity, favs, and comments. Things can be removed from explore and will as if they were never there. Inclusion in certain high traffic groups has been known to act as a poison pill.
The magic donkey does not like to be played to give an image or person exposure. Appealing to an enthusiast population, say model railroads, may also trigger an administrative removal since response may be spuriously high for photos with few redeeming qualities.
As for rank...highest is #1 and lowest within the explore window is #500. The link regarding the science of explore tells how photos float into the window and how they float out.
It is probably best to not overthink the process. Upload your stuff, be judicious in group submissions, and enjoy the brief fame when it happens.
Steve