[strav]

I'm assuming you have the book- 2-C-0 Paragraph 4, or did you want more?

Thanks for the reply Mike
I have the book and also the the Ben Doyle video “How to Build a G..O.L.F. Game” where he demonstrates the angle of the shaft in relation to the shadow of the milk crate and says “That looks straight – that is leakage - this is straight”. Is he saying the same as 2-C-0 i.e. that Clubface imprecision during impact will permit Compression leakage?
Did he recognize that leakage would occur simply by looking at the angle of the clubshaft and are there other ways we can demonstrate leakage?