To be honest there are names familiar to me when I get matched with them, I think to myself that "this most likely won't go well" or I may say something on my discord, etc...but I don't say it during the match- that's just terrible morale for the team overall.
I may not care for that particular player but I will still try my hardest in that match to win >.<
If people just stop trying in the middle of the match, I tend to report them and every time I've had a GM respond to me within 15 minutes.
