User blog comment:TheTobarMethod/Guide To ADC/@comment-3541335-20130223193417/@comment-90.40.192.63-20130224002217

in the   teamfight the ap carry is THE person you shouldn't focus with your adc unless he's close and unloaded all his CD

i tell you this as  I main   mostly mids :  an ADC who focuses me is godsent i just turnback and  kill him outright for being dumb enough  to  get in range of my burst   (with most ap carries)

the ADC job is to stay on the side  and keep  max AA range while hitting to be safe and DPS as logn as he can: the longer you live the   more damage you deal.