For many amateurs, like myself, who pay for their golf balls, I try to play my them for as many holes as possible. It is not that I am really cheap, but $5.50 Cdn a golf ball can get expensive if I willy-nilly change my golf all. This propensity to use my golf ball as long as possible leads to a less that favourable playing condition for my white gold. Hence, I pay attention to when I can replace my ball and when I cannot. Not surprisingly, there is a rule that covers this topic and one that if you are in competition is very important.