I get terrible lag sometimes, I just said that when I get this "3 bullet to kill advantage" thing, which is not very often, the game is easier to do well, but I can still do good on a mediocre or bad connection and so can other good players. I see players who have host or other connection advantage but still do terrible because they are bad players.
I even made a thread about being on ONE bar while everyone else is on FOUR. Look it up. Now THAT can be called "bad lag".
The difference is I can normally adapt to it. Sometimes I can't, when it's really bad. But connection is an overused excuse, just like camping.