Tickrate troubles? Blizzard is monitoring.
Of the many things Overwatch does right, there are still some issues with the game’s network performance, mainly the tickrate. If you’ve found yourself facing death when you thought you escaped or dying before your ability was triggered (even though you activated it), then the tickrate may be the issue.
Overwatch‘s tickrate is set to 20.8 Hz while Counter-Strike: Global Offensive, another competitive FPS< is 60 Hz. It's been a long-standing issue for some time now, even though 60 Hz is included for custom matches. Blizzard responded to GameSpot for the same and said, “Tickrate is a very important topic for the team. We added a 60 Hz refresh rate feature in Custom Game late in beta. We continue to diligently watch the feature and would love to get more feedback from our players. We encourage players to test the feature themselves so we can collect more data and help improve it.”
Until then, just try to be a little bit more nimbler than usual while avoiding harm.