it's quite easy to cheat on a multiplayer game. Just find a good AI program and make the opponent play with the AI.
there might be a solution to this: "lightning chess" but it's not a good way to decide who's better player...
some people needs long time to think...
Yes I totally agree. Lightning chess is a possibility. But before we change the nature of the tournament... let me just say that I can review every game, and if I see something fishy, I will disqualify the cheater.