If the latest research by the U.S. Golf Association is any indication, the rules governing the design of grooves on iron and wedge faces are about to change. And do not expect them to get more lenient.
The U.S. Golf Association's final report of its nearly two-year-long study of grooves (in conjunction with the Royal and Ancient Golf Club) confirms its preliminary findings, namely that the U-shaped grooves on iron and wedge faces have a significant spin generation advantage over V-shaped grooves. The report was sent to manufacturers last month, and a portion of the report was obtained by Golf Digest through industry sources.
In its conclusion, the report reads, "modern groove and face treatment specifications represent a significant performance improvement in terms of spin generation over more traditional V-shaped grooves."
Those words echo precisely the conclusions of August's preliminary report. (For more on the debate about U- vs. V-shaped grooves, and what it means for you, read "Here V Go Again," from Golf Digest's November 2006 issue.)
The final report does not include any proposal for a rule change, but it does seem to indicate a fundamental change from the USGA's position on grooves 20 years ago. At that time (during the so-called "square grooves" debate), Stuart Bloch, then chairman of the USGA's Implements and Ball Committee, actually termed any differences between U-grooves and V-grooves "inconsequential."
When asked about the different conclusion, USGA senior technical director Dick Rugge said time changes a lot of things. "People used to think the world was flat," he said. "We have a better means of researching than what we had 20 years ago. We have more tools and more researchers. We have three PhDs now working on this. We didn't have that back then."
Manufacturer representatives contacted by Golf Digest and Golf World declined official comment on the contents of the report. Others familiar with the findings believe the USGA will act soon to soften the current groove profile on irons and wedges.
Rugge did not provide any specific timetable for a rule-change proposal or even suggest that there would be a change at all. But he did suggest that a meeting with Arnold Palmer several years ago prompted him and his staff to research the issue further.
"When Arnold Palmer came to our building and shook his finger at me and said, 'Allowing U grooves was the biggest mistake we ever made,' it did make me want to take a look at that issue," Rugge said.
The latest research suggests that all facets of groove design were considered during the investigation, which involved the testing of 70 different face and groove configurations. The report concludes that decreasing groove spacing, increasing groove depth and width, and decreasing the edge radius of each groove all increase the spin potential. The edge radius has to do with the relative sharpness of the top of the groove, or the groove's relative squareness.
Rugge says the USGA research showed that an intermediate groove, what the report calls a "V-like" groove, may provide a possible answer to the spin-generation concerns. That could be an important development in that a true V groove is much more difficult to mass manufacture than the current U groove. In tests with tour players, the report states, "it was demonstrated that it was possible to manufacture club faces with groove profiles that were not V-shaped yet performed like V-groove clubs when used by golf tour professionals in lies in the light rough."
Another crucial element in the grooves research is the idea that a change in the groove rule will not impact average golfers in any significant way, but could have a more profound effect on the way the game is played at the highest level. According to a USGA study of amateur players at the Walt Disney World Palm and Eagle Pines golf courses, only 13.1 percent hit the green from shots out of the rough from 100 to 200 yards. The PGA Tour average for similar shots is 49 percent. Also, because the urethane-covered ball used by tour players spins much more out of the rough than the typical ionomer-covered ball (like those with Surlyn covers) preferred by most average golfers (more than two-thirds, based on a study of recent Golf Datatech industry sales figures), average golfers often don't use the equipment that can generate the most spin.
"It's a way of addressing the problem where the problem shows up and not affecting anybody else," says Rugge.
The next step in the process could be a rule proposal, a likely step in the near future given the amount of time and research the USGA has devoted to the subject. Rugge says any rule proposal would allow for individual manufacturers to work within a set of guidelines, not simply mandate a one-size-fits-all procedure. The key elements most likely will be a combination of limiting the cross-sectional groove volume and more clearly defining the guidelines for groove edge radius. Of the latter, Rugge said, "We've never really defined it very well. We've only defined it with the finger test," referring to the Rules of Golf stipulation that a face design "must not have sharp edges or raised lips as determined by a finger test."
Officials at Callaway, TaylorMade, Nike, Titleist and Ping did not have a comment on the USGA's report.
Mike Stachura is Equipment Editor for Golf Digest.