The resilience of some and the absolute inflexibility of others

All this stuff about a trampoline or spring-like effect on the face of modern drivers can be a mite confusing, especially with Michael Hoey having to change to a different driver for the forthcoming Walker Cup matches in the US. So, we will attempt to offer a little enlightenment, with the help of Dick Rugge, senior technical director of the US Golf Association.

Essentially, it has to do with the coefficient of restitution of the club-face after a ball has been fired at it. For instance, if the ball is travelling at 100 mph before impact and 75 m.p.h. afterwards, the clubface is deemed to have a coefficient of restitution (COR) of 75 per cent.

In the case of persimmon, the COR is about 78 per cent and for early steel-head clubs, 78.5 per cent. First-generation titanium was measured at 79 to 79.5 per cent. But when titanium heads became larger and the face thinner, it was discovered that the COR had soared to 82 per cent. On that basis, the UGSA set a COR limit of 83 per cent, two years ago.

According to Rugge (pronounced Ruggy), some clubs have since been marketed with a face little more than a tenth of an inch thick, so producing a COR of 84, 85 or even 86 per cent. And boffins are predicting the figure could go as high as 88.

In terms of performance, this means that a player driving the ball 289 yards with a wooden club will get an additional 10 yards from an increased COR of 83. "If he continues on with the highest COR clubs we've seen so far, that will be a 305-yard hit," said Rugge. "And at the perceived maximum, it will be 309 yards - an increase of 20 yards from the wood. We've drawn the line at 10 yards."

But what of the average golfer who hits the ball 220 yards? He will get about three-quarters of the benefit, but only, and here's the rub, if he happens to be smack on the sweet-spot, which is a circle no more than half-an-inch in diameter. As Rugge conceded: "Not only must you be able to swing pretty hard, you must find the sweet spot reliably and repeatedly."

That, essentially, is the reason the controversial ERC drivers have been banned in the US and not by the Royal and Ancient. As R and A secretary, Peter Dawson, put it: "We try to take into account all the constituents that have an interest in the subject, as do the USGA."

Then came the crucial point: "They just think of the elite golfers, while we don't." In an interview in the current issue of Golf International, Dawson rejected suggestions that the R and A's decision was based on fear of litigation.

"I can honestly say that it did not have any bearing on our decision," he said. "I sat right through the whole decision-making process and it was not a factor." Meanwhile, Rugge made the fascinating observation: "Golfers have been tinkering for 500 years, but today's tinkering isn't done in somebody's workshop. It's done in front of cad-cam computers by PhD's." Having seen man and computer during a visit to the Callaway plant in Carlsbad three years ago, I know precisely what he means.

And the final word? "The R and A and the USGA need to get together," said Jack Nicklaus this week. Amen to that.

"If I were a musician, my instrument of choice would be the triangle, because it's kind of low-key, like me."

- A suitably modest comment from Tiger Woods, given his share of 25th place behind David Duval in the British Open last Sunday.