Golf's governing bodies still need convincing over the need to make changes to balls so that they do not fly so far, especially as "the distance issue has plateaued" in recent years.

The Royal and Ancient Club (R&A) and the United States Golf Association (USGA) have continued to monitor the situation since concluding in a joint statement four years ago that "any further significant increases in distance at the highest level are undesirable."

The two organisations have asked manufacturers for prototype balls which fly 15-25 yards less, and their own testing has included experiments with bigger and lighter balls.

But Peter Dawson, the R&A's chief executive, said today that data gathered from the American and European tours has shown that "as we predicted, the distance issue has plateaued.

"In the last three years it has hardly moved. The 2005 season was one of the most exciting we have seen, and there are no symptoms of a game in decline. The top players are still coming to the top, but if there is one issue that does concern us it's the dis-connection between success and driving accuracy."

The top three earners on the US Tour in 2005 - Tiger Woods, Vijay Singh and Phil Mickelson - finished 188th, 147th and 161st in driving accuracy, proof that what matters most in the modern game is power. They finished second, 16th and 26th respectively in driving distance.

The easiest way to counter that is in the set-up of courses and there will be no rush to halt technological advances in balls and clubs, Dawson insisted. "There is a lot of research going on. We'd like to understand as much as we can about the science, so that if it does become necessary to do something we will know what we're doing," he said.

"It's common knowledge that we asked the manufacturers for prototype balls and we are in the process of receiving them. That's at an early stage. We are continuing to expand our knowledge, and it's something we need to get right. If we felt something needed to be done the implications are massive."

Steve Otto works in the R&A's research department and is a former NASA scientist. He has confirmed that testing of all sorts of balls has been conducted at the USGA's test centre.

"We wanted to see if there was a magic ball out there," he told The Guardian. "People thought there might be a solution out there that would keep the game the same but also address the question of distance.

"We looked at making a bigger ball and a lighter ball. We looked at balls made from different rubbers and at balls with different dimple patterns."

Now, however, it is the manufacturers' prototypes that are being examined as a possible way forward - if it is thought necessary.

Many tournament courses have become obsolete, and others like St Andrews and Augusta are being stretched to combat the extra distance balls are being hit - part of the problem being that, as in all sports, the top performers are becoming bigger, stronger and fitter.

While there may have been a levelling-off overall, a look at driving distance statistics on the US Tour tells its own story.

Last year there were 26 players who averaged more than 300 yards per drive. In 2004 there were 14, 2003 just nine and in 2002, 2001, 2000 and 1999 John Daly was the only one.

Daly also led the four previous seasons, in 1996 with 288.8 yards. That would have put him 98th last season.

One thing is for sure, the golf ball debate will go the distance.