No-one knows and no amount of guess work is going to be able to find it out. There are lots of different tales of who/how/where they got bumped but there is no definitive answer. I am not even sure is is worth speculating upon. My "strategy" is to start watching my flight about a week out - and even then I think that is over-egging it - but at T-72 I am watching it like a hawk to try and react to anything I may find unpleasant. And then pray.