Home run derby hitting

Question
I am trying to plan a home run derby for our Little League & I want to make it as fair as possible. I am trying to find out what the best distances by age to use, the ages range from 9yrs. to 16yrs. old.Can anyone help me with where to find outwhat  the average distances are, or has anyone ever done this & how did you do it.Thanks for any help.

Answer
Radar sports has a contest that combines the fastest pitch with a contest ... the pitch- a -thon fundraiser.
There are several distances you can pitch from at those ages.
Too hard to email.... Needs to be explained.

If you would like to discuss this and the pitching distances please call me at 516-678-1919