I was sitting at the dinner table today, waiting patiently for my food and playing with a golf ball on the table, I discovered that the ball would balance when rested squarly on a dimple, but when the ball was moved slightly to "off" the dimple, it would roll.

It occured to me that when you putt slowly, the size and shape of the dimples could easily effect the line of the putt because the ball surface is not true.

Is this correct, and is there anything that can be done to minimise the problem. To me it seems like another good reason not to putt too gently and to use softer covered balls.

Jeremy.

Dear Jeremy,

My article on the "dimple error" in putting might interest you. Basically, the settling of the ball as it stops happens into a cushion of grass, not a hard flat surface like a table, so the irregular surface of the ball from dimples doesn't matter enough to cause a problem. Nor does the dimpled surface cause the ball to roll off line, for the same reason. The only real source of error is when the flat metal surface of the putter face contacts the "raised edge" of a dimple, as this slightly misdirects the line of the putt. But this only matters enough whyen the putt is over about three feet in length, as before then the misdirection compared to the closeness of the hole and the size of the hole swamps the misdirection error. Also, this dimpled surface does not matter for putts over about 5 feet, as then the force of the blow of the putter against the cover material of the ball smushes the edge of the dimple enough so that the misdirection again doesn't matter. Between 3 and 5 feet, the dimple error misdirection is still too small to worry about in comparison to the golfer's ability to aim and putt straight with good touch, and even if the golfer is perfect in these departments, the irregularity of the green itself (as in "the rub of the green") is a larger source of error than the ball dimple.

So, perhaps it MIGHT matter to a perfect putter making a 4-foot putt on Augusta National on a Sunday, but probably not even then. The chances that the dimple edge will align in just the right way to cause a left-right error big enough to matter is less than 10%, and the chances of the edge aligning in a harmless orientation is at least 90%.

If you use a soft cover ball of a soft-insert putter face, you pretty much rule this error out. In addition, Dr Norman Lindsay explains on his website Lindsay Putters how "grooves" on the face of the putter also reduce or eliminate this source of (minor) error. You can also use Bald Eagle putting balls, as they have six points on the ball without dimples, or you can align the ball along a "seam" where the dimples have minimal coverage on the ball surface.

Cheers!

Geoff Mangum
Putting Coach and Theorist
PuttingZone
http://puttingzone.com
Golf's most advanced putting instruction.