February 16, 2009

The Old Squeeze Play

Whatever became of golf ball compression? Manufacturers still use it, but only internally. For consumers the numbers' game is gone

Bubba Watson compresses a ball that doesn't bear a telling number.

Bubba Watson compresses a ball that doesn't bear a telling number.

Remember when balls were made out of balata, had wound cores and were labeled by compression? An 80- compression ball was for women, a 90 was for most men and the strong players (or those playing on a really warm day) chose 100-compression balls.

It was all a lie.

"Compression was the biggest myth in golf," said Dean Snell, TaylorMade's senior director of R&D for golf balls, looking back 15 or so years. "Back then tour balls labeled 90 or 100 compression were more like 65 or 75. Now they truly are between 85 and 105 in most cases."

Conversely, two-piece, Surlyn-covered balls from that time were between 90 and 100 compression. Today they are in the 50-to-70 range. The reason for the change is that designers have found ways to make the cores softer without losing the speed in the rubber composition—something not possible years ago. The softer cores can keep the spin down off the driver, thus helping distance while reducing any "rock-like" feel.

So what exactly is compression in a golf ball? More importantly, why does it matter and why don't companies post the number anymore? Bill Morgan, senior VP of R&D for Titleist golf balls, offers this tutorial.

"Compression is a golf ball's resistance to being deformed at impact," said Morgan. "When a golf ball is struck, the side in contact with the club flattens [compresses] during impact. How much it compresses is estimated in a laboratory test in which golf balls are squeezed. It's a pretty good test method, but unfortunately it flattens both sides of the golf ball, which is different from golf. So how much do you squeeze? And how fast?"

Morgan points out there is no industry standard for measuring compression and that different companies have different devices that measure different things and get different results. "That's enough of a reason to stop publishing compression values," he says. "Every golf-ball designer uses compression specifications as one of the many design elements needed to achieve the desired performance characteristics of golf balls, so it is still important. It just doesn't make sense if we start talking numbers."

Designers use compression two ways. One is to predict performance. According to Snell, spin off the driver almost always can be estimated based on compression. It's also used to try to achieve a certain feel in a ball. That, however, is a bit tricky because every part of the ball affects its feel.

So does what a player hears. "In our tests what a golfer calls feel is often more associated with sound than any tactile effect," said Morgan. "Some golfers make feel comments only after observing trajectory height or behavior on the green. Feel is a difficult property to define."

And we no longer use compression to help define it.

Spotted

Vijay Singh rarely changes shafts, but he replaced those in his driver and 3-wood to a prototype from SRI Sports, parent of Srixon and Cleveland Golf. Singh wanted a lighter driver shaft (75 grams, down about 10 grams from his previous model) to increase his ball speed.

Bag Room

Three TaylorMade staffers had good weeks at the AT&T National Pro-Am after changing drivers. Sean O'Hair finished T-10 using a 10.5-degree r9, and Mike Weir finished second playing an r7 Limited model. Retief Goosen finished third after going back to TaylorMade's r7 SuperQuad. ... Tour pros rarely use something other than "tour-caliber" balls, but Steve Allan did just that at Pebble Beach, using Titleist's NXT Tour, which sells for $30 a dozen. ... No fat jokes, please: Kevin Stadler last week used a putter from the Heavy Putter company. True to its name, the club weighs substantially more than a conventional putter.