Darts is clearly a very boring sport to watch. This is a game where you have to hit a target and various regions have different amounts of points. Essentially the objective is to score exactly 301 or 501 points before the other guy, and yet they have all these complications with "sets" and "legs". You could just say "winner is the first person to get 15 games", but no, it has to be more complicated, the cynic in me says, to keep interest up.
Playing darts is another matter. I once worked with a keen darts playing amateur who had the privilege of having Eric Bristow visit his club. He said, Bristow could put a dart in any region on the board at request, pretty much 100% of the time in an exhibition context. Basically, Bristow was banging in treble 20's at will.
So, why did Bristow ever lose a darts match, you ask. It's because professional darts is all about handling pressure. It's not physically demanding, but it is mentally as tough as any sport there is, including curling.