There's a exp penalty that reduces the exp you get by 75% if you leave too many Overwatch matches.
What I want to understand is, what constitutes leaving. If my game crashes and I have to kill it in task manager while I am in a game, does that count as leaving? If I leave the match during the hero select screen (pre-prep period), does this still count as leaving? Do I have to wait the entirety of the PoTG as well as the commendation screen then leave to not get a penalty?
What constitutes "leaving"? I'd like to know so I don't get penalties.