User blog comment:Fistful of Force/You don't always have to focus the ADC first./@comment-203.218.134.109-20120812152641

focusing who is situational, if the enemy ADC is like 0-10 then obv u dont have to care about him (unless the game is 80mins and everyone has full build) on the other hand, if the tank is 0-10 but has some serious cc (like amumu/ali), it wouldnt be a bad idea to get him out of the fight asap for hes lack of items and feed could render him easy to burst down

The main rule is to focus the guy who is most fed/dangerous except for the tank, even if u are an assassin, you still have couple choice including bursting the ADC or the APC first, if they are both not fed, then perhaps helping ur team in bursting their fed off-tank or jungler isnt a bad idea either