well snowbird has has 4 Quads and 6 doubles now that list is kinda of old.
also continous vertical and not just overall vertical drop should be included. Where in Park City, Deer Valley, or the Canyons can you ski 3000 vertical feet in one run? at snowbird you can do it over and over again.
as for Big Emma the number was found by Powdr that the over all steepness is 25.5. The far left side know as pepsi challenge by the locals quite a bit a steeper and has cliffs when snow is low.
and also 27 percent of snowbird terrain is not even close to beginner. There is excactly 3 main routes you can take with a strong wedge turner down the main mountain (wilbere loop, West 2nd South, and Easy street), all of them are easy slopes connect by cat tracks. everything else since it requires a parrellal finsh to your turn IMO is blue or higher.