From the FAQ Home section over to the right ------->
Your Average Score will be based on multiple best scores within ONLY your current Tier, not scores that you shot when in previous Tiers, which better reflects your current skill competing with the tee boxes and green speeds in your current Tier. Your Average Score will be based on ONLY your best scores, so completing a bad round will not negatively impact your Average Score or Tier. So be sure to finish all your rounds and gain the extra experience points, as a bad day won’t matter. Please note that scores from the Best of Par 3 stroke play course will not be counted towards your Tier ranking.
It's worth taking a quick stroll through the FAQ; the answers to a ton of questions regarding the game play are answered there already. The FAQs are fairly well organized and referring to them occasionally can save you a bunch of time and grief.