How New Grooves Affect You



I appreciate your weekly e-mails and the simplified technical information you provide golfers. I have tried to make sense of the new groove rules, but am still a little confused as to how it will affect the average golfer, like me. Can you help?

– Dave 


Let me try to explain why the rule was changed and how you will be affected.

The USGA and R&A decided, based on a statistical analysis comparing the top money winners on the PGA Tour with their driving accuracy numbers, that the correlation between driving the ball in play and winning was decreasing.

For example, the average ranking in driving accuracy of the Top 10 money winners on Tour was:

48.3 between 1980 and 1989;

77.5 between 1990 and 2002; 

120.4 between 2003 and 2006

The conclusion drawn by the governing bodies based on this information was that being in the rough was not a severe enough penalty for the very elite golfer (i.e.,  the PGA Tour player). In an attempt to correct this perceived problem, the USGA decided to limit the size of grooves to half the present volume, and reduce the sharpness of these grooves for clubs with lofts greater than or equal to 25 degrees. This will result in decreasing the spin one can achieve out of the light rough. The performance will be equivalent to that of the old “V” shaped groove adopted in 1942.

This will be the first rollback in equipment performance specifications in the history of the game with the intent of persuading the best golfers in the world to drive the ball in the fairway more often. I do not know if the change to the groove specifications will accomplish this goal. There are few, if any, Top 10 money winners who are not already trying very hard to keep their drives in the fairway.

The rule change will initially be implemented as a condition of competition, beginning January 1, 2010, for  all USGA Open championships (beginning with the sectional qualifying events), PGA Tour, LPGA Tour and equivalent professional events. A similar condition of competition will be adopted as of Jan. 1, 2014, for all  USGA amateur championships. The rest of us will be required to change our clubs prior to Jan. 1, 2024, if we want to play in accordance with the Rules of Golf.

If you intend to enter the U.S. Open, The Open Championship (British Open), U.S. Senior Open, or U.S. Women’s Open in 2010, then you will need to buy a new set of clubs except for a driver and putter – so your Frankly Frog putter is safe. However, I would suggest that you buy a new set of clubs (about $1,200) AFTER the local qualifying rounds since they are exempt from this condition of competition in 2010. If you make it to the next level (sectional qualifying), then you will need to spend the money for a new set.

The set will need to have the new grooves – 50 percent smaller and with rounded edges (between .010 and .020 radius) – for clubs with lofts of 25 degrees or more. Clubs with lofts less than 25 degrees will only require smaller grooves without sharp edges – not the precise radius between .010 and .020 of an inch.

Is this confusing?

To clear up (or add to) the confusion, you will not be able to buy a new set of clubs manufactured and shipped from the factory after Jan. 1, 2011, if they do not conform with the new groove specifications (this was changed from Jan. 1, 2010).

How is this change going to affect you, the average golfer, since no one will be confusing you with a Top 10 money earner on the PGA or Champions Tour? The answer is somewhat dependent on the ball type you use (soft-covered balls will spin more than hard-covered ones), your ability to impart some backspin on the ball from the light rough or the fairway, and how much money you are prepared to pay for a new set of clubs.

For most of us, the ability to put a lot of backspin on the ball with our wedges is not one we have perfected, but it does happen now and again. This occasional demonstration of brilliance will no longer be present using the new grooves from the light rough – from the four-inch rough it doesn’t matter what groove configuration you have even if you are Tiger Woods.

Another way it will affect you, should you choose to abide by the Rules of Golf, is that you will eventually have to buy a new set of clubs. Hand-me-downs will need to be stored in the attic unless the USGA decides – as it might – to change its mind closer to the 2024 deadline.

For a disruption to the game of this magnitude, we can only hope that the Top 10 money winners and their friends on Tour become more accurate with their drives next year, and the money list and the accuracy statistic are better correlated; otherwise, we have gone to a lot of trouble for naught. One would have thought that an experiment for a year or two at the very elite level might have been the prudent way to proceed.

Let's see what happens by the end of 2010. 

For more explanation about the groove rule and how it will impact you, go to

– Frank 


Frank Thomas logo Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf. Thomas is chief technical advisor to He served as technical director of the USGA for 26 years and directed the development of the GHIN system and introduced the Stimpmeter. To email a question for possible use in an upcoming Let's Be Frank column, please email


Frank Thomas