Originally Posted by
Josephmay
2) You can get a pretty good idea of how many medallions that are are the flight by looking at premium seating occupied in the main cabin.
No, you really can't. Further to answering your follow-on questions, there are routes (and times of day) where Diamonds and Plats are riding in the back. You can't assume that all Diamonds and Plats got upgraded at 5 days to leave you competing only with other Golds for upgrade space.