let me tell u what I know, some games r using servers provided by the same company who made the game, this helps alot when playing online and doesn't give the host any advantage, on the other hand there are some games that doesn't use servers, like Gears of War and Call of Duty, these games depends on how close the guy u r playing with, that's y most ppl play with ppl in their area 2 get rid of lag but the host won't lag at all, only other ppl will lag if the host's connection isn't enough 2 keep up with all players in the game