SweetiePie: Nevertheless, if one selects any player by random, regardless of tier, and checks their stats, they will find that perhaps 90% or more of the players tested will have a score average lower than their best ever 18 hole score.
You may already be aware of it, but that is due to the fact that 9-hole and 18-hole rounds both count as one round. It's pretty safe to say that's it easier to shoot well over 9 holes than it is over 18. Players will record repeated rounds on Kiawah's Back 9 and will post 28's, 29's and 30's despite the fact that the best they can muster on the front side is a 34.
And of course, this is just one of the many reasons why a player's average should be taken with a grain of salt.