The USGA’s New Grooves Rules Simplified:
What has changed?
The USGA and R&A have modified the rules on the size and sharpness of the grooves on wedges, irons and clubs with lofts of 25 degrees or more.
They have reduced the allowable size and volume of the grooves, and have reduced the groove edge sharpness.
Why was this change made? The larger, sharper grooves made it easier for players (particularly expert players) to spin and control the ball out of the rough, which has made driving accuracy and the ability to keep the ball in the fairway less important.
How will it affect the average golfer?
Most golfers will not notice a difference in the grooves changes. The changes that are in place now will not become permanent rules changes until 2024. Club manufacturers will be allowed to produce and sell their remaining stock of clubs until the end of 2010, and golfers will be allowed to use them until 2024.
Timeline for groove rule changes:
January 1, 2010: The new rule is in effect for PGA Tour events, Nationwide and Champions Tour events, Major Championships, the European Tour and other Major International Tours.
January 1, 2014: The new rule will be in effect for most Professional Events and Expert Amateur events, as determined by the tournament committees.
January 1, 2024: The new rule will go into effect as a permanent equipment specification in the rules of golf.
So, basically unless you are planning to play on tour or enter a top amateur event, you do not need to worry about the new grooves rule until 2024.