1) Average is reset when tiering up.
2) For average, a certain number of your best scores is used - 25 for Tour Pro. Once you reach that number, your average can only decrease until you tier up.
3) For average, gross scores are used, 9 hole scores are doubled. You 35 and 36 at STA will have had an influence as a 70 and 72.
4) Par3 and Par5 scores do not count in. That's why the 77 did not change nothing.
5) Next tier - Master - at 67 average.