Double entrants happen but how often? I that that most of the evil cheaters would be deterred by the lack of valuable prize. I would think the would didicate their evil cunning to something profitable
I once entered the open and under 1700 section of a tournament. The TD arranged for both my games to be at the same table. In the first round I beat a 1900 rated player in the open and lost to a 1300 in the under 1700. I forget what happpened in the rest of that tournament. But in the next tournament I focused on the under 1700 and won every game. Now that m USCF rating is 1931 I am forever barred from under 1700 sections.
I agree with phys but others won't. If we had such a system here, I'd be forced to play in Master tourneys which doesn't agree well with my fast-play game. I'd accept it though ... I'd just have to get better!
Although there is something to what OnlyJoking suggested, I only play in tournaments ... mostly because the games are easy to pick up and there is some kind of goal and organization.
Cheating seems to be natural to humans. I think most do it just for the 'sport'. On Queen Alice, they will still cheat even if you take every incentive away and make the site very boring for the rest of us.
That said, I think the OPEN tourney is just an invitation for every kind of cheating imaginable. I'm curious why honest players even enter them!