To play the GM's in that event, you have to qualify through some earlier events. And open tournaments are nothing new. They are usually played by the Swiss sy

To play the GM's in that event, you have to qualify through some earlier events. And open tournaments are nothing new. They are usually played by the Swiss system, which means you play each round against an opponent whose current score in the tournament is the same as yours. That means the most suspenseful games are in the last round, between the players with the highest scores. That tends to mean GM vs GM, since to be at that scoring level you first have to beat a string of regular masters, IM's, and so on. It's not that simple. (This explanation though is slightly simplified vs the real world details).