Well, the first thing that comes up in my mind is if there are no supports I tend to say GG lol. I dont know why, just wanted to give pressure to my teammates in order to buy courier.
And another thing is Russians. Jesus, I hate many of them so much. I occasionally lost my 150 mmr due to them. We were winning during that time with the score of 23-32, but... WE LOST THE MATCH :( I was really enraged and searched another Ranked match. But lost that one again and due to russians because there were in party and I was alone...