Back in the 80's, a shopping mall would offer players the opportunity to have their serve speed measured with a radar gun. They'd post the highest speeds. One time the guy in front of me even got his into the 130's! But most people were surprisingly slow. Including me. I got into the upper 70's, but didn't break 80. Also, they listed the fastest speed for a female, and it was 80, even. A lot of people self report serves of over 100 mph. How do they know? Might a lot of people be mistaken over their serve speed?