The change was directed toward elite players and emphasizes the importance of hitting the ball in the fairway.
Research over the last several years indicated that sharper, deeper grooves in irons produced so much spin that players could hit into the rough and still control iron shots to the green.
USGA president Jim Vernon said that while driving accuracy in the 1980s was as critical to success on the PGA TOUR as putting, over the last five years, the importance of accuracy was of hardly any consequence.
We undertook a world-class research effort to discover why that might have happened, he said. Our attention focused on grooves.
The R&A and USGA did not ban U-grooves, also know as square grooves. Ping won a court case in the 1980s over the right to use such grooves in its Ping-Eye 2 irons. Rather, the size of the grooves must be slightly smaller and have rounded edges instead of sharp edges on wedges through 5-irons.
Phil Mickelson and Jim Furyk were among those who responded favorably to the change.
They cant keep making golf courses longer, because not every course has a $20 million budget, Furyk said. And they cant keep us from hitting the ball far, because theres enough engineers and R&D and technology that keeps us getting longer. If you can limit the amount of spin on the ball and make the guy play from the fairway, its probably a good avenue.
Mickelson favored the change because he said it would bring skill back to shots out of the rough.
I have no problem with that because I feel like its a challenging thing for a player to judge shots out of the first cut of rough or out of the rough, Mickelson said. Is the ball going to spin? How is it going to come out?
Mickelson said tournaments have tried to emphasize driving accuracy by growing the rough so thick that all players, no matter how skilled or how strong, have to play the same shot by chopping it back to the fairway.
Masters champion Trevor Immelman suspects the new grooves might indirectly limit distance.
Players are using harder golf balls that launch higher off the tee, and the grooves give them enough spin around the greens. But if the smaller grooves produce less spin, he believes players might need a softer cover on the ball that wont travel as far.
As we change the grooves, were going to have to start maybe looking at the way our golf ball is performing, he said.
John Solheim, chairman and CEO of Ping, said he was disappointed with the rules change and will study it more closely.
However, I already know it moves the rule book backward, he said. How does this help the average golfer enjoy the game more?
Vernon said he did not anticipate any lawsuits.
We think were in good legal position in case a manufacturer does feel necessary to file a lawsuit, he said.
USGA officials said it was the first rollback in equipment since a brief experiment in the 1930s to reduce the weight of the golf ball. That was deemed ineffective, and the rule was scrapped.
The grooves policy is effective in 2010. The USGA and R&A said it would be enforced only at major championships and tour events around the world, such as the PGA Tour, European PGA Tour and LPGA Tour. It would be enforced at events like the U.S. Amateur in 2014.
As for the recreational player, irons made before 2010 will conform to the Rules of Golf until at least 2024. Consumer research shows that only 2 percent of all irons are older than 15 years.