Golf World's E. Michael Johnson does a nice job of covering the groove issues, with some surprising comments from Tour players about the change (Davis Love is against it, Jason Gore for it).
But here's the more interesting stuff in the cover story:
If implemented, the rule likely will not have the impact rolling back the ball or reducing clubhead size (two ideas consistently bandied about) would. But it is groundbreaking territory nonetheless. The proposal is the culmination of a two-year research study, and the end result is that the USGA wants to reduce the impact of grooves to what it was 20 years ago--in some ways a make-up call for the perceived mishandling of the groove situation by the USGA in the late 1980s and early 1990s.
Dick Rugge, the USGA's senior technical director, refuses to point fingers or lay the blame at his predecessors for the groove situation spinning out of control. "The equipment is much better today and that made it much easier to do the research," he said. "We have more resources and more engineering people. And we had the impetus to do it, which was 20 years of data from the tour. That showed us there was a problem."
The USGA has never admitted there was a distance problem, even with 20 years of data and a long list of people who know the game well telling so. And we're in year 5 of the ball study, yet they pick grooves after 2 years and little demand for a rules change.
The data Rugge speaks of is a correlation coefficient using the PGA Tour's money list and four primary statistics--driving distance, greens in regulation, putting and driving accuracy--since 1980. It revealed that while as recently as the late 1980s accuracy was as much an indicator of success as putting, the relationship between accuracy and success is now almost nonexistent.
Therefore, data should show that rough isn't costing the top players much in the way of shots.
Oops, this chart accompanying the piece would seem to say otherwise: