Hi Joey,
for your information the way the average score in computed is quite simple (I just hope to be clear enough). Perhaps the information can be found on this forum, I didn't check (sorry if I am redundant) but it goes like this.
The average is computed using only your X best ranked/scored games (played in CC, tournaments, alone etc). Notice also that if you subscribed to a tournament being pro, for example, and then your turn tour pro at some point and you still play this tournament as pro (because the tournament is not yet ended), those games count in your tour pro average.
The number X depends on your tier (see below for the numbers I know for the moment). When your number of scored game are below this X value, your average is a normal average: you add all your scores and divide by the number of game. Pay attention that a score obtained on a 9 holes should be extrapolated to a score obtained on a 18 holes by multiplying it by 2 (so 33 on a 9 holes will count as 66).
Once you have played X games or more in your tier, your average will NEVER increase anymore because only your best games are taken into account, so at that point it can only decrease or stay stationnary after each game. This also explain why when you have played X or more scored game, your average can decrease even if you do a score above your average (for example if your average is 70 and your worse score among your X best scores is 80, if you do 75, this 75 score will replace the 80 and your average will decrease even if 75 is larger than your actual average score of 70).
I didn't pay attention about that when I was amateur and pro, so for these two tiers I do not know the value of X (but this is quite low). What I know for sure is that when you are Tour pro X = 25 and when you are Master X = 40. I do not know yet for higher tiers because I am still Master but X increases as you get higher tiers.
Now to be complete, you advance tier when you have played at least X scored games AND when your average score is below some value. Again I am not completely sure about the numbers for amateur and pro (so I report what I found on this forum).
When your average score is equal or smaller than 100 you go from hack to amateur
When it is equal or smaller than 80 you go from amateur to pro
When it is equal or smaller than 72 you go from pro to tour pro (sure about this one)
When it is equal or smaller than 67 you go from tour pro to Master (sure about this one)
When it is equal or smaller than 63 you go from Master to tour master (will check soon)
When it is equal or smaller than 61 (or perhaps 60) you go from Tour master to legend (hope to check one day)
Hope this help,
Best regards