Joe,
I need to know exactly where do you put both the left thumb and the right thumb on your grip?
(no name)

Dear No Name,
First of all, never wrap the thumbs around the shaft like a baseball bat, the thumbs should stay close to the forefingers. You can view this in any magazine or book that has illustrations (including my book). As you take your grip, view the shaft in terms of clock positions, with 12 o’clock being the side of the shaft that is away from your body. The tip of the left thumb should rest on the shaft at approximately 1 o’clock, and the tip of the right thumb should rest on the shaft at approximately 11 o’clock. This is true for both right handers and left handers. Your thumb and forefinger on both hands form a “V” which should point somewhere between your back shoulder and your chin. You can adjust the position of this V to correct hooks or slices. To help correct a slice, move the V to point to the back shoulder. To help correct a hook, move the V to point more towards the chin.
Joe