Picture this:
You are holding badlands yard after being pushed out of mid. Both teams have uber and are jockeying for a position. Its tense, your mouse hand is sweating. Ninja says "Im gonna go make a play." and you believe. You believe in your heart because you know its the only damn chance you have to push back into mid and win this round.
Then, quick like you never had time to think, "Forced the uber. Demo down. Scout down. Medic down. Push guys."
BOOM. Ninja just won you the round. Damn that was a good choice of you to pick him up. Yeah, its already decided, hes on the team.