Don't you use your "highest" average at tournaments? I don't see an issue unless a bowler was to purposely bowl on a difficult pattern/difficult house soley for the purpose of bagging. Although I tend to believe that after a period of time (such as over the course of a season) bowling on tough conditions, one can "forget" how to score. In the end, I think it all works itself out. When it comes down to it, one still needs to perform at the tournamnet, under tournament conditions.
S^2
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Currently residing in Spring, TX