The skill of driving accuracy has become a much less important factor in achieving success while playing golf than it used to be. USGA analysis of statistical data measured by the PGA Tour since 1980 shows that historically, driving accuracy was similarly correlated to winning as putting. Beginning in the early 1990's, however, driving accuracy became much less important. Today, the correlation between driving accuracy rank and winning rank has reached a very low level.

In March 2005, the USGA informed club manufacturers of its interest in the area of spin generation, and that the USGA would conduct research on this topic. Since that time, the USGA and its rulemaking partner, the R&A, have been jointly conducting significant research into how groove designs affect spin and other performance characteristics. In August 2006, the USGA and the R&A sent a technical report summarizing the progress of the research to club manufacturers. The USGA and the R&A sent an additional research report in January 2007. The research findings are available on the USGA website at: http://www.usga.org/equipment/notices/notices_and_announcements.html

The research clearly demonstrates that for shots from the rough with urethane covered balls (the type of ball most used by highly skilled players), modern, square or U-groove clubs result in higher ball spin rates and steeper ball landing angles than V-groove designs that were predominantly used in the past. The combination of a higher spin rate and steeper landing angle results in better control when hitting to the green, creating less challenge for shots from the rough. As the challenge from the rough has decreased, driving accuracy has become less important.

Therefore, the USGA is proposing to change the rules governing grooves. The objective of this change is to limit the performance of grooves on shots from the rough to that of the traditional V-groove design. While currently conforming clubs with V-grooves would continue to conform under the proposed new rules, the changes do not mandate the use of a V-shape. Rather, they permit club designers to vary groove width, depth, spacing and shape to create clubs that conform to this proposed groove rule. Under this proposal, most of the current rules governing grooves would remain unchanged. There are two key additional groove specifications proposed for clubs other than driving clubs and putters:

• The total cross-sectional area of a groove divided by the groove pitch (width plus separation) would be limited to 0.0025 square inches per inch.
• Groove edge sharpness would be limited to an effective minimum radius of .010 inches.

For more detailed information, please refer to the complete proposed rule changes and measurement method (Proposed Groove Rule, Groove Measurement Procedure Outline).

Proposed Implementation

It is proposed that these new groove rules become effective for all new clubs covered by this rule change that are manufactured after January 1, 2010. A Condition of Competition would be added to the USGA Rules of Golf to become effective January 1, 2009. This would allow a Committee to require the use of clubs that conform to the new groove rules for competition events conducted after January 1, 2009. Similar to other equipment-related Conditions of Competition, the USGA would recommend that the Condition apply only to competitions involving expert players. .

Status of Currently Conforming Clubs

The USGA is considering how to treat clubs that currently conform to the Rules of Golf, but would not conform to the proposed new rules. This consideration would be made for the vast majority of golfers who would not likely be affected by the proposed Condition of Competition, as well as for golf clubs already in use and /or manufactured prior to the proposed rule implementation date. The USGA is proposing to allow their use for a lengthy (at least 10 year) period of time. As part of this Notice, the USGA is requesting opinions, comments, or any other type of helpful information from golfers, manufacturers, retailers, golf organizations, and other interested parties regarding the future status of such golf clubs.

Written comments regarding the proposed change to the rules governing grooves should be sent to the USGA, attention Dick Rugge, P.O. Box 708, Far Hills, NJ 07931, Fax 908-234-0138, e-mail: drugge@usga.org. Written comments received later than August 1, 2007 will not be considered.