When the little green men took you up in their flying saucer they removed you to a zoo where your environment is peopled by robots, maintained by robots and chess is only played by robots.
Sadly it will probably turn out that you are yourself a robot who has simply been programmed to imagine that you are not robotic.
I just hope that the entities you amuse in your zoo have some sort of soul (or a brain at least).
And all players play a particular same opening like a chess engine play when set to a certain elo strength
Uh, that's called an opening line . . .