You are compared with 99 other people chosen randomly. If you are better than everyone else in a specific domain, you win 1 million €/$. What do you choose?
It doesn't state it would just be one game, nor that you would have to win, just that you had to be better, which is easy to demonstrate with a program that measures the error level as backgammon is a game of skill with a large chance factor and not a game of chance.