Once a layer reaches a new tier the counting of the average starts over. Until you reach the maximum amount of ranked rounds for that tier, all of your scores will count, including high scores.
We use an algorithm to determine when
a player is eligible to move to a new tier as well as computing the average,
which takes into account a number of factors including number of ranked games
played. These numbers scale by tier, so
it's necessary to shoot a lower average to advance and to play more games to
reach higher tiers. For example, when
you reach Tour Master, you will need to play a larger number of ranked rounds
than you had as a Master, maintaining a low average, to tier up to Legend.
Additionally, in response to WGT player feedback
about sandbagging (misrepresenting one's true ability to gain advantage by
playing at a lower tier from closer tee boxes), WGT is using more than just
ranked stroke play scores to determine each player's average score and
appropriate tier ranking.
For obvious reasons, WGT is not sharing exact
details of these changes, but they include factoring in scores from players who
perform well in tournaments and challenge games for credits. We still encourage the community's feedback on
Sandbagging, but believe this is an important step to reducing the practice and
keeping the game fair.
Finally, most of our top players have posted close
estimates for players to try to gauge their progress in advancing tiers. Here
is a good thread to read:
http://www.wgt.com/forums/p/9085/707139.aspx#707139
WGT