Speaking as an ex front office manager, I can say that if there was a better room available and we knew we weren't going to sell that room during your stay, we'd upgrade you without any special request on your part. The key here is "knew we weren't going to sell", so the later you showed up for a single night stay, the more of a no-brainer it was to upgrade. But here's the thing: if you've reserved via a credit card and not actually made a payment and there are more incoming guests than available rooms (without getting into why that happens) you get 'bumped', meaning we send you somewhere else that night. The only people absolutely not bumped were people who had already made a payment (contract law).

So... if you're 100% sure you're going to sleep in that hotel that night - and aren't sure how booked the hotel is for your dates - make a deposit. Worst case, if there's a convention in town, you get the room type you reserved.

Finally, if you're rude to the front desk staff, act like they're your servants, even if you've done all the above, and there are better rooms available, expect to be in the standard room you've reserved, but not in the best location (e.g., next to the elevator).

Also, for anyone considering the hospitality industry as a career, consider something else. Most of the jobs are long, inconvenient hours, high stress (in the sense of having to apologize for things you have no control over). I've seen it destroy relationships and health.