>How the hell does it end up 50% wins all the time?
Because that's what the system was designed to do. If you're winning more than 50% it means that some percentage of the time, the game can't find 5 people who are better than you to put in a game. You'd have to compete at a semi-pro level to get this to happen.
Also, I realized that I feel around ten times worse when losing than how good I feel when winning, so the expected derived pleasure from the game is really really negative, so I scaled my playing down a whole lot.