hi robert
its a book and a video cd that worked out that all good playes have a 3 to 1 swing , tiger is a 24/8 and hogan is a 21/7, monty is a 21/8 and garcia a 25/7.
the closer you get to a 3 to 1 swing tempo the better to hit the ball.
i though this unlikly when i heard it but i bought the book on amazon and was suprised and it did make a lot of sense.

there web site www.TourTempo.com.
have a look ? it was on here i heard about it. maybe have a look back and you see some thinks others have said about it.
i found it was good and i'd put it behind, hogans fundemental and dave plez short game and putting bible,s as books that hane helped my game most.
if you want to know any more let me know.
the cd not much good but books ok, get you to swing in time with some beeps, 21/7 or 24/8 or 27/9 or even a slow 30/10.

bill