Chinajohn:this makes it complicated.
I didn't notice these details before. Another item in this context is credit wins. No clue how these impact average and tiering, but they do!
Let me add another verse to Complication Blues:
Back in time (a few years later than dot), the first Nation tournaments were so secret that they would not appear in the score histories. Of course they counted to the average, but for a while you had to check before average calculation if such incognito scores might be in the mix. Lucky enough that this was before anti-sandbagging and Par3/5 courses were introduced ;)