• The Force •
Feel the Force‚ Luke‚ Feel the Force.
No‚ I’m not Obi-Wan-Kenobi‚ but that’s the advice I’d give to both Luke Donald and you. “The Force” is my name for a new way to practice that is based on Tour Tempo and Yale professor Bob Grober’s paper titled “Towards a Biomechanical Understanding of Tempo in the Golf Swing.”
My dad found the Yale study on the internet. Professor Grober‚ working with biomedical engineering professor Jacek Cholewicki‚ had conducted an independent study verifying Tour Tempo’s main premise (the 3-to-1 backswing-to-forward-swing elapsed-time ratio) and offering a scientific model for the mechanical forces involved. Dad was so excited that he immediately called Yale and got permission to post the paper on our website.
Bob‚ it turned out‚ was a golf enthusiast who just happened to be one of the world’s top applied physicists. For that reason—and because he has published two subsequent papers on putting mechanics that support our thesis that tournament pros employ a 2-to-1 tempo ratio for their short shots—Bob is my go-to guy when I’ve got questions on the science of tempo. Not long ago‚ for example‚ I had to prepare a Tour Tempo presentation for the 2011 PGA of Holland Teaching Summit. I started with a basic outline from my 2008 lectures to the PGA of Sweden and the World Golf Fitness Summit‚ but I like to spice up my presentations with fresh data and the latest discoveries. Going over my notes‚ I remembered something that Bob had told me—how if you pictured the golfer’s body as a spring‚ that spring would coil and recoil in a 3:1 time ratio … or something like that. Wanting to get it right‚ I fired off an e-mail to Bob.
He wrote me back: Relevant to your question‚ if you imagine the body as a giant spring … wind it up (backswing) by applying a constant force‚ F1‚ and then unwind it (downswing) with a force of different magnitude‚ F2‚ and in the opposite direction‚ and if F2 is twice the magnitude of F1 (i.e. you push down twice as hard as you push back)‚ then the ratio will be 3:1. As F2 gets larger than twice F1‚ then the ratio will get larger.
We traded a few more e-mails‚ and he sent me links to his new papers on putting. They both confirmed the 2:1 tempo ratio‚ and to achieve it you had to use the SAME force on the backswing and downswing. F2 had to equal F1.
Talk about counter-intuitive! If your tempo is a 2-to-1 ratio‚ you’d assume that your downswing would require two times more force than your backswing. Similarly‚ you’d associate a long-game tempo ratio of 3-to-1 with a force profile that is also 3-to-1.
But that is NOT the way it is.
As a competitive long-driver‚ I had always assumed that my downswing required three or four times more force than my backswing. In that respect‚ I was like my mid- to high-handicap students‚ who think they have to throw everything they have at the ball on the downswing.
No. Your downswing needs only twice as much force as the backswing.
Force Profile will be published by Tour Tempo in the near future. Until then‚ may ‘The Force’ be with you!