Overwatch is making changes to its matchmaking system right now. The Overwatch matchmaking will make changes in the way the points are given to support. Normally it is quite difficult to track the amount of involvement that a support has in a team environment.
While DPS players stack up their statistics, Supports role in the team is not clearly shown in the metrics.
“We’re still playing around with it, I don’t know, maybe someday we will count damage, but right now we have it so that, like, crowd control abilities – you know, if Mei has somebody frozen, or if Reinhardt has somebody Earthshattered, Junkrat’s trap is on you, anything that removes your control – that will trigger an assist. Or things like Mercy damage boosting you, or a Zenyatta Discord Orb.
Sometimes there can be that guy who’s just contributing way more than you realise, and the game doesn’t always tell you that. So it’s easy to get grumpy at them, like, ‘whoa, what’s Zenyatta doing on our team?’ You start to see all those assists pop up in the kill feed and you realise, like, every single kill is because he has a Discord on somebody.”
Source : IGN