If your teammate is in a 1v1 don't run up and 2v1 unless absolutely necessary.

Am I the only person annoyed with teammates who will come and "help" me in a 1v1. If I'm locked in a 1v1 I'd rather not have the person get revenge in about 3 seconds and win the fight. The only way I see a 2v1 necessary is if their breaking or if I'm at dangerously low health.