“The data provide objective answers to where strokes are being lost, but the fact is if you’ve got two hours to practice, you probably won’t start hitting the ball longer or straighter in that time period,” Broadie said. “But you could probably get better at your putting or chipping in two hours of practice.”

Broadie’s research is the result of hundreds of hours of work by several associates, a professional computer programmer and graduate students who assisted in technical aspects of the project. He wanted to assess the difference between a PGA Tour player’s game and that of an amateur who shoots 75 or 85 or 100. The PGA Tour charts every shot by every player in every tournament, and Broadie obtained that research dating to 2003. He then had average golfers of all handicaps, from 11 years old to 70 years old, start charting all their shots at various New York metropolitan area golf courses, although most of this was done at his home course, the Pelham Country Club. Using Google Earth renderings of golf courses in the area and topographical booklets he made up, average golfers making notes during rounds on the golf course could record exactly where every shot went  in the fairway, in the rough or out of bounds, and how far from the hole.

Using the Golfmetrics program, Broadie and a few others entered the rounds in a computer, documenting every putt, bunker shot or other kind of shot  and the result. It took a few years, but there were more than 43,000 shots recorded.

Then Broadie worked backward from there. Because he had all the golfers’ average scores, he could determine how far the average low-, middle- or high-handicap golfer hits a tee shot (see the accompanying graphic above). He could determine at what distance various golfers sink half their putts (8 feet for the PGA Tour pro, 6 feet for the player with a handicap from 0 to 9, 5 feet for those with a handicap of 10 to 19, 4 feet for someone with a handicap from 20 to 36).

Perhaps most valuable, he could analyze the value of each shot of a golfer’s score.

The sample used for Broadie’s research is limited geographically, and women make up less than 10 percent of the group studied, a figure Broadie says he wishes were higher. But over all, he defends the sample as representative.

“I’m confident there is nothing atypical about Pelham Country Club golfers and others in the area I sampled,” he said.

Maybe, although this being golf, there are no doubt many who will quarrel with Broadie’s methods or results, which he presented to the World Scientific Congress of Golf in March 2008.