The change was directed toward elite players and emphasizes the importance of hitting the ball in the fairway. Research over the past 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 past 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 over the right to use such grooves. Rather, the size of the grooves must be smaller and have rounded edges instead of sharp edges on wedges through 5-irons.
"They can't keep making golf courses longer, because not every course has a $20 million budget," Jim Furyk said. "And they can't keep us from hitting the ball far, because there's enough engineers and (research & development) 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, it's probably a good avenue."
Phil Mickelson favored the change because he said it would bring skill to shots out of the rough.
"I have no problem with that because I feel like it's a challenging thing for a player to judge shots out of the first cut of rough or out of the rough," Mickelson said.
John Solheim, the 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?"