MrFunnyWobbl: Fantastic thank you. [...] or is that strictly an access ability?
As the amount of backspin generated varies so much due to the differing club attributes, ball attributes and shot type and power, even thinking about it gives me nightmares, lol. But there is a lady who has a vast blog on the subject, and I believe Gary may have used some of the information there in his program, so I would suggest you find a nice comfortable chair and prepare yourself for a long read. CLICK.
Unfortunately I have never used Access but perhaps we could discuss this further via pm.
Thank you.