Welcome aboard !
There are some links here : https://steadyoptions.com/forums/forum/topic/5432-john-de-ratio/?do=findComment&comment=125118. The posts are not in the right thread, sorry about that.
I'm still working on the call ratio calculator, but it's available in beta to get feedbacks.
So to answer your questions : the % return and the ratio are taken from @TrustyJules spreadsheet that is available in the Rational Trader thread, and it's using 8 earnings cycles for now.