When both teams lose, who wins? That might sound like an oxymoron, but the latest Overwatch adjustment to competitive play is aimed at exactly that scenario. It’s possible when playing on maps with an Assault component like Hanamura to have both teams fail to capture an objective at all… which raises the question of who wins. In an effort to make things fair, a change was already made so that the team which made more progress would be declared the winner… but that led to a problem wherein it was essentially a job for defenders to always have someone on the capture point so the attackers couldn’t make progress.
The next change upcoming requires at least 33% progress on the capture for it to “count,” meaning that if the enemy team slips someone on for a tiny sliver of capture, they’re still behind. So if both attacking teams manage to partially capture the objective, but one hits 10% and the other hits 40%, the team who hits 40% wins the round. The various potential tie scenarios are all discussed in the official rundown, which should put your mind at rest if you stay up at nights thinking about this problem.