Remove Backfill

Jeff Kaplan has stated that backfill is a required function for the casual modes, but they are working on finding ways to minimize the chances of being backfilled into the end of a match:

Are you talking about Quick Play or Competitive? Your quick play profile does not track losses. In Competitive which is supposed to have no backfill, a 2-minute timer starts when a player on your team leaves. If that timer expires, you can leave and still take the loss on record (with the appropriate SR deduction), but you yourself will not be suspended from Competitive Play.