Originally Posted by
sambagrrl07
It happened to me on a revenue ticket earlier this year. Reports are that OLCI but not downloading/printing a boarding pass before you get to the airport MAY increase your chances (it worked for me).
The not printing boarding passes makes zero difference to upgrades, since you are shown to DUT as firmly on board. But it does allow you to play around with seat selection. So if you select a seat next to another Goldie (careful analysis needed here) and they need a couple of seats together, then that obviously helps. Also if you are upgraded before departure - usually it happens in the final hour so you would have to hold a boarding pass at this point - then not having printed (etc) your boarding pass allows you to select seats in the new cabin more easily.
Bear in mind this is a robot however. If you like your seat, I would OLCI and do the boarding pass to get it out of the way.
I should also point out, it is quite common for BA to zero out a flight when they know they are pretty much full, even if there are actually a few spare seats, since they need to allow (e.g.) staff duty travel seating. So it's not unusual for a flight with say 4 spare seats to be zero'd out since they know that by the time it gets to the spin cycle, it will all come out in the wash.