>Meaning, if I place 20 cups on the bar, how many queens will be produced? 20? Just trying to plan how many mating nucs to prepare!
Every queen breeder wishes they could predict. It depends on your technique, the age of the larvae, the density of the bees in the starter, the weather, the climate, the time of year...
So I guess it is like predicting the number of hives that will successfully overwinter!

Another question. Assume you have more queens then room in your mating nucs, and you use cell protector cages to catch some of the virgins before they die or are killed (
http://www.brushymountainbeefarm.com/Cell-Protector-Cages-10/productinfo/153/ ). What is the best way to bank them? What is banking, how long can you do it, how many queens to one bank, etc..? I have found little about this on the web.