"A couple times a year" you will get an upgrade without asking. If you ask at the desk at check in, this will rise to "once in a while." If you have a special reason, e.g. wife is along on a business trip, and call ahead, this will rise to a "fair shot." If you are on vacation with the rest of us, get in line for a "crap shoot." If you desire a President's Suite, google "snowball's chance."

To be fair, I've won some pretty great rooms under the "crap shoot" rule.