Only skill should improve golf scores, Johnson tells Newsday

Stan Johnson, professor of mechanical engineering and mechanics and a
consultant for 11 years to the U.S. Golf Association, was quoted several
times last month in a lengthy article published in Newsday, the Long
Island, N.Y., newspaper, prior to the U.S. Open golf tournament.

The article, titled “The Physics of Golf,” detailed USGA’s efforts to
limit the amount of assistance that golfers receive from innovations in
golf-equipment technology. Or, as Johnson says, to try to make sure that
golfers’ improvements result from “skills, not equipment.”

Johnson is currently conducting research to develop mathematical models
that describe the speed, angle and degree of spin with which a golf ball
leaves a club head. His goal is to help USGA monitor an ever-growing
stream of improvements to golf club heads and golf balls to make sure
that new equipment follows USGA size, weight and performance
regulations.

At USGA’s research facility in Far Hills, N.J., Johnson and his
colleagues fire golf balls of different constructions at varying speeds
against a 100-pound steel block. They determine the “coefficient of
restitution” by dividing the post-impact speed of the ball by the
pre-impact speed of the ball. This ratio varies according to a ball’s
material and its construction, the speed with which it is launched, and
the material of which the metal block (which represents the golf club
head) is made.

“We’re trying to solve a production-line efficiency problem,” says
Johnson. “We need models in order to more efficiently monitor the
improvements that are being made to golf equipment.”

Several years ago, Johnson and his colleagues found that golf balls
bounced five or six feet per second faster off metal plates made of thin
titanium than they did off plates made of steel. They wrote a paper on
this “trampoline effect” and presented it at the 1998 World Scientific
Congress of Golf in St. Andrews, Scotland. Some drivers with the
“trampoline effect” have been outlawed by USGA.

Johnson will deliver a paper on his current research next month at the
2002 World Scientific Congress of Golf in St. Andrews.