ProudVet77 says, "Cook it upside down for the first 1/2 of the cooking time. What happens is all the fat and juice from the dark meat on the bottom baste the breast."
Hadn't heard that before.
Thanks much, PV77.
It works quite nicely, but I usually only do a 15lb turkey or so. Remember to oil the top of the bird and the rack so the skin on the breast doesn't stick to the rack. If you carve the bird in the kitchen it doesn't matter.