Golf balls: fighting Lou Gehrig's Disease on the PGA Tour.

John Feinstein, who has done perhaps as much for golf writing as Arnold Palmer has for golf, puts down his driver in his latest work and delivers instead a lovely little pitch shot dead to the hole.

Feinstein chose broader themes in his earlier books on the sport: the pleasures and the pains of playing on the professional tour (A Good Walk Spoiled), a history of the four most important tournaments (The Majors), a behind-the-scenes look at the preparations for the U.S. national championship (Open: Inside the Ropes at Bethpage Black).

In Caddy for Life, Feinstein gives us nothing more ambitious or less compelling than the story of a golfer and his caddy, and of how, after more than two decades of a successful, easy going boss-employee relationship, they suddenly found themselves facing catastrophe.

The golfer is Tom Watson, who was, in the interregnum between the supremacies of Jack Nicklaus and Tiger Woods, the greatest player in the world. The caddy is Bruce Edwards, who was unknown to the public but a popular figure on the pro tour and, because of his long relationship with Watson, a giant to his peers.

Then, early last year, Edwards was diagnosed with the crippling disease ALS (Lou Gehrig's Disease), and as the word spread--and as he and Watson shared a moment at the U.S. Open that would have shamed any Hollywood scriptwriter who dared to imagine it--their roles were reversed. Before Edwards died on the first day of this year's Masters in April, Watson began carrying the load for him.

Feinstein takes his time with this and to good effect. Two-thirds of Caddy For Life takes place before Edwards gets the bad news at the Mayo Clinic. In these pages we learn why, despite the fact a caddy's life consists of long hours, menial tasks, and too many weeks when there are no bags to carry, it still exerts a tug on American boys looking to light out for the territory.

Edwards was raised in a middleclass family (his father was a dentist, his mother a dental hygienist) which did things together, joined a relatively inexpensive country club, and sent all its children to college.

All except Bruce. One weekend caddying at the Greater Hartford Open and he was hooked. Joining the tour, carrying another man's bag, enjoying the life of the open road was for him. As far as his parents were concerned, he might as well have run away and joined the circus. The concept was so foreign to them, in fact, that even many years later, after Watson's success had guaranteed Edwards great respect and a steady income, they kept expecting him to return to his senses and go to college.

It was Edwards's good fortune that he joined the tour when prize money was rising to a point where not just the winner of a tournament, but all the players finishing in the top 10 or 20, could make a decent income. A small percentage of this devolved on the caddies, the smartest of whom quickly learned how to share expenses, live cheaply, and make it to the next stop down the road.

Edwards also benefited by hooking up with Watson early in his career--they met at a tournament where Edwards appeared with no money and no bag to carry--when the young Stanford graduate was just beginning to discover that his dream of trying to make it on the pro tour was not so far-fetched after all.

Watson soon developed a large public following because of his exuberance and intelligence, as well as his brilliant and often thrilling play. His epic victory over Jack Nicklaus in the 1977 British Open at Turnberry--one of five British Opens that he won--came after one of the great battles in the sport's history, and his chip that landed in the 17th hole at the 1982 U.S. Open at Pebble Beach to beat Nicklaus again was the stuff that dreams are made of. Watson also had a tenacity, a willingness to practice for hours after a round, that taught Edwards there was more to life than yardage markers and club selection.

For his part, Edwards developed an insight into Watson's personality and temperament, and learned when to kid his boss about his latest misadventures and when to give him a pep talk. Though they did not live the same lives--Watson was a family man and a millionaire, Edwards a bachelor living from paycheck to paycheck--the life they shared benefited them both. Theirs became one of the longest-lasting golfer-caddy relationships in modern golf.

The years passed, their lives changed. His best days behind him, Watson cut back on his schedule and Edwards went to work for Greg Norman, the charismatic Australian golfer who jetted all over the world from one tournament to another. Edwards didn't enjoy it and two years later asked Watson, who was then preparing to join the Seniors Tour, for his job back. He also married, disastrously, and Watson was part of the support group that helped him through that.

Then, just as Edwards was reunited with Marsha Moore, a woman he had met on the tour years earlier, and they began speaking of marriage, he was diagnosed with ALS, and his life was set on fast forward. The wedding was hastily arranged at a tour event in Hawaii--a Who's Who of professional golfers joining them on the beach at Kona for the ceremony--word of his illness began to spread, and he and Watson became the subject of a frenzy of media attention.

Determined to help his friend, Watson began researching ALS, using his star power to call attention to the disease and rallying his friends and colleagues for fundraisers. Then he went to the U.S. Open at Olympia Fields south of Chicago in June 2003 and did one thing more.

At the age of 53, Watson shot a 65 on the first day of the tournament to tie for the lead. Nobody his age had ever done such a thing before. And then he went into the press room, where hundreds of reporters and a national television audience were waiting, to say very little about his round and a great deal about Edwards and about ALS.

He had the bully pulpit, Watson said, and he wanted people to understand the need for more research. He also said--and these are words I never expected to hear spoken at a golf press conference--that one reason there is not enough research into ALS is too few people contract the disease to enable the large drug companies to realize a profit from a cure.

Feinstein spent much time with Edwards's family, his friends, his buddies in the caddy shack, and the PGA golfers who know him best. For the most part, though, the story comes down to Edwards and Watson and how life brought them together, first in one way, then in another.

In this writer's accomplished hands, small is beautiful.

Ron Rapoport is a sports columnist for the Chicago Sun-Times and a sports commentator for National Public Radio's "Weekend Edition Saturday." His book on Bobby Jones will be published by John Wiley & Sons next year.