My main server for the first 4 years of play was USeast2. I almost never left it to play on other servers. About 2 years ago I started playing on USeast, USeast3 and USsouth. What I noticed is that I had a decrease in some whites and an increase in others. How did I notice that you ask, well I track my whites by item, class, month and year, so I noticed the changes. (yeah its pretty sad that I do that but I got in the habit and kept doing it).
I have written Random number generators for programs I have done over the years and used SEEDs to help generate.
My theory is the SEED is based on the PLAYER NAME and the SERVER NAME. It seems to me that by going to the different servers I have increased and decreased some whites. !!! BUT !!! that is a guess and we will never have confirmation from DECA as to how they generate the RNG.