It used to be: win one big game —early in the season— in a weak schedule, and make a big bowl game. Now it's lose one big early-season game in an otherwise weak schedule. Upsets are much more likely early in the season.
Having said that, the G5 race is not over by a long shot. Only the highest-ranked G5 CHAMPION will get in. So Boise must win the MWC championship game (and of course they will be highly favored, but it's not a gimme). Otherwise Army / Navy / Tulane / Memphis ? will slip in.