Ben ...
it's because you average is based on the best 10 of your last 14 games .... every round you play will change that 14 round set. The 4 highest scores out every given set of 14 aren't counted. Evidently your 4th round, even though it was the best of the 4 you played, pushed another low score out of the 14 . I posted a response and an example to a similar situation yesterday ..http://www.wgt.com/forums/t/7496.aspx
thanks......now I understand why so many players quit on the 9th or 18th hole.....Thanks