I had a best share at over 10 billion, was the highest I ever had.. and it was after I reduced my S9 frequency to 550, which I thought was weird..
So when that happened I wasn't sure if that share raised my Herp more than usual.. Wasn't sure if the higher share was better for my herp than a slightly higher hash rate..
And that's called sheer coincidence. Luck is luck. Altering settings doesn't change luck. Increasing your hashrate increases your chances of a high share; end of story.