Probably just who you play against/with. Or how lucky you are. It always finds people closes to you with the lowest ping right? If everyone near you has a low ping then everyone is going to be on the same level. Just a theory.
I don't have issues unless i"m in a party. My team is on the opposite side of the country and I always have 3 bars. It's laggy for me about 40% of the time those matches. But we're also playing at 2:00am and there's only like 500 people spread out all over the country so I'm sure that has a factor in it.