Bets

Why bother? Vitaly has already suggested a clear option: everyone plays each other in a round-robin format, we count the points, and award 1st and 2nd place. The only thing I would ban is draws, so there isn't a situation where a draw suits both players (because I'll be the first to agree!).

I see one major drawback in this system. If someone loses many games, they will be forced to finish what is already meaningless. Firstly, such games will not be interesting to watch, nor will they be interesting for the participants to play. Secondly, there will be opportunities for match-fixing (I don't think this will happen, but still).