ALMOST FROM THE BEGINNING he was doing it. At 10 months old, the story goes, Eldrick Woods climbed down from his high chair in the garage of his family's house in Cypress, Calif., grabbed hold of a child's plastic toy club and began precisely mimicking his father's golf swing, lefthanded -- a piece of legend given to us only by Earl Woods, since no one else was in the room at the time. Its plausibility is bolstered, however, by the fact that some five years earlier and 100 miles south in San Diego, a boy named Phil Mickelson had done exactly the same thing. Watching his father hit balls, Mickelson at 18 months had also copied his dad's swing, mirroring it lefthanded. Mickelson, a righty in every other way, would stick with that lefty swing, becoming the most accomplished southpaw in the sport's history, winning four majors and 40 PGA Tour events. Woods, though, was different.

After two weeks of swinging his plastic club lefthanded (this is, again, according to Earl), Tiger apparently grew dissatisfied with the motion. As the father looked on, his son waddled to the other side of the ball and -- in the part of the tale that always engaged Earl the most in the telling -- switched his hands, moving the right below the left, intuitively finding the proper grip. Earl called to his wife, Kultida, elsewhere in the house: "We have a genius on our hands!"

IN THE LEAD-UP to the 1994 U.S. Amateur, held at the TPC Sawgrass, The Oregonian newspaper reported: "Eldrick 'Tiger' Woods conquered all the worlds of junior golf, and then he did a curious thing. He changed his swing." He had started the process 13 months earlier, under his new coach Butch Harmon. The goal was to exorcise Woods' swing as a teenager -- a long, spidery, loose-limbed arc that, while powerful and at times brilliant, contained a host of extraneous movements. Already Woods had his sights set on the pro circuit. Already Jack Nicklaus' 18 major-championship trophies were his professed goal. In his precociousness, he was making the kind of change that certain players attempt only once they get their first taste of PGA Tour-level competition. They see how astoundingly good the world's best truly are -- how they strike the ball with such purity -- and decide they must seriously upgrade their swings. History has shown that most will come to regret that decision.

The Mike Douglas Show, 1978: 2-year-old Tiger unveils the swing that would be the blessing -- and the curse -- of his career. CBS/Getty Images

WITH ALL DUE respect to the 14 majors, 74 wins and historic victory margins, the greatest act of Woods' career, the constant and complete reinvention of his game, has been almost universally reviled. Other than the lurid soap opera of his private life, arguably nothing has brought Woods so much derision as his major swing changes. But now, nearly two decades after that Amateur in Florida, Woods appears to be on the verge of completing the unthinkable: disassembling, reconstructing and mastering his golf swing for the third time in his career. Not only has no other player ever attempted such a thing, no other player has ever conceived of it -- though perhaps a better way of putting it is: No other player would ever want to conceive of it.

We're not talking about the endless tweaks and minor revisions that all players, from touring pros to dedicated hacks, are forever visiting upon their swings. We are talking instead about the conscious decision to undergo a structural overhaul, wherein a player transforms the very shape and pattern of his swing via a tedious and labor-intensive process that carries with it all manner of psychic complications.

Long grooved into the frontal lobes of golf's conventional wisdom is the notion that every person has a "born," or "natural," swing. The standard analogies are of fingerprints or DNA or the Design of the Almighty. "Nothing works," says Curtis Strange, "like your God-given golf swing." Among gifted players who achieve low handicaps, this notion is especially powerful. So much so that in many circles, to meddle with your natural swing is to meddle with your soul -- to dive too deep and risk discovering things about yourself that maybe you'd rather not.

At age 19, David Gossett won the 1999 U.S. Amateur at Pebble Beach. A year later, he carded a 59 during one of his rounds at the PGA Tour's Qualifying School. A year after that, in his rookie season, he won the PGA Tour's John Deere Classic. This success notwithstanding, he became convinced he needed to change his swing to become a world-class ball striker. He now has trouble breaking 80, and when he plays a competitive round at all, it's likely on the Hooters Tour. As he said to a reporter in 2009, "Chasing the almighty, elusive great swing is not real."

Craig Perks won the Players Championship in 2002 and then, unhappy with his ball striking, made "radical changes to be more consistent," according to quotes in 2007. He retired from the game later that same year.

Scott Verplank, who won a tour event while still an amateur, became convinced he needed to hit the ball higher to be successful at the uppermost level of the game. He changed his swing, lost his card and spent five years fighting the so-called driver yips -- whether its causes are psychological or physiological is debated -- that pros fear more than perhaps any other demon. Though he came back to fashion a modest career, with three tour wins since the '80s, Verplank, now 48, never fulfilled his early promise.

Swing changes have afflicted more than just young players craving upward mobility. They have brought down top-10 players and Hall of Fame-level champions. Four-time tour winner Chip Beck wanted to heighten the trajectory of his shots so he could hold the hard greens at the majors. David Duval, once the world's top-ranked golfer, tried to add a reliable draw to his repertoire of approach shots. Ian Baker-Finch wanted more distance off the tee. The great Seve Ballesteros sought the one-plane consistency promised by an obscure golfing tome. All underwent drastic swing changes. None ever won again. Three of the four (Duval, Baker-Finch, Ballesteros) came down with the dreaded driver yips. Beck left the tour to sell insurance.

"More players have ruined their careers striving to find the perfect golf swing than have gone on to become successful," says Jim Furyk, a player with perhaps the most unorthodox swing in the contemporary game -- an ungainly double-hitching loop that nonetheless moves with an unassailable rhythm and produces one of the most consistent ball flights in the history of the sport. His father remains his coach. They have never tried to change his swing.

June 1997, pro swing change No. 1. Tour events prior to change: 17. Wins: 5. Winning percentage: 29.4 percent. (Majors: 1. Wins: 1. Winning percentage: 100 percent.) World rank at time of swing change: 2.

IMAGINE, FOR A moment, Tiger Woods hitting balls in the summer of 1997 on the private driving range near his house in the golf-as-lifestyle residential development known as Isleworth, just outside Orlando. Not two months earlier, he had won the Masters, his first major, by a record 12 strokes, and he had just watched a videotape of that final round. It was then -- while sitting in the studios of the Golf Channel, whose offices were near his home and whose video archives he would often study -- that Woods, rather famously, decided that his swing was not good enough, not for his purposes, at least.

In that video of the Masters, where others saw otherworldly dominance, Woods saw only a flaw -- that he was relying on timing, that he could have a superior round only on those days when the movement of his arms was perfectly synced with the rotation of his hips. The lower body's twisting back and forth, that massing of energy and then its release, is the source of all good players' power. But Woods, one of the most athletic specimens to play the game, could snap his hips through his swing with a speed as yet unseen in the sport. He'd been using this whipping motion all his life. It had long been seared into his gray matter. Still, his arms had to keep up. When they didn't, they would, as he termed it, get "stuck" behind him, coming through late, the clubface open, blasting the ball away in great curving vectors to the right. Woods was also blessed, or cursed, with what is called kinesthetic sense -- a body awareness so heightened, in his case, to also be called genius. Thus he could sense when his clubhead was out of position, even at speeds of 130 mph, and adjust his hands to compensate. But he could also overcompensate, yanking his arms hard enough to overtake his hips, shutting the clubface at impact, imparting dramatic right-to-left spin, sending the ball zinging out some 200 yards before dive-bombing to the left at blazing speed, caroming into trees or adjacent fairways or the skulls of unsuspecting gallery members. The only way to avoid the hooks or the blocks was to have days of great timing -- flipping the hands at precisely the right moment, like a man throwing a quarter through the window of a moving train. Woods had the talent to experience whole weeks of great timing -- flipping coin after coin through the train windows -- as happened at Augusta. Unlikely, however, even for Woods, was to have whole seasons of great timing.

Harmon too had studied the tape and had arrived at a series of modifications that would add up to a remedy. He counseled caution: "It's not going to be easy for you to make this change and still play through it." Woods said, "I don't care." Against Harmon's wishes, Woods insisted on installing everything all at once ... We'll do the whole recipe now. Start with the grip; weaken it, rotate hands to left. Adjust the takeaway, the shape of the move: Shorten it, setting the hands at the top in a position that will put the clubface squarer to the target. Less sidespin, less backspin. More control. Simpler. Tighter. Repeatable. A machine hardwired to make the same move again and again. A swing that won't get stuck.

"We tore it all apart and built it up," Woods would later say.

He had his predecessors. Others had succeeded in rebuilding their swings and come back to play championship golf. But they were an exceedingly rare species. The most famous example, Nick Faldo, who replaced the upright lash of his youth with a flatter, almost robotic strike under the tutelage of David Leadbetter in the mid-1980s, played very little competitive golf for more than a year as he went through the arduous renovation process. Because Woods didn't uncritically trust every recommendation from Harmon -- his own prodigious knowledge of the swing, according to Harmon, allowed Woods to diagnose the problems of other players with ease -- he wanted to test these new moves as soon as possible in competitive rounds. That was the Woods way. He would use the PGA Tour as a proving ground. It would require methodical work, the unlearning and relearning of muscle memory he'd spent his life acquiring. That might have been the point.

AMONG THE SCORES of clichés golf has spawned is the classic, attributed to Nicklaus, that the game is 10 percent physical and 90 percent mental. But this tidy truism hardly comes close to describing golf's savage cognitive dissonances, of which the swing change is the ultimate. A psychologist would say that a swing change, whether a simple grip adjustment or a massive shift in the backswing, is a process of habit development and habit suppression. Golf psychologist Gio Valiante likens the latter to going to AA: 20 years after quitting, recovering alcoholics know the merest swig could trigger their old ways. A biomechanics Ph.D. would say that a swing change means adjusting your motor program. A neurologist would say it involves the wrapping, or thickening, of something called myelin -- a fat compound that insulates neural pathways in the brain. "Muscle memory" is the colloquialism for all these things. The ultimate goal is to make the new swing as automatic an act as possible. "Advanced performers are unconsciously competent," says Bob Rotella, psychologist to many golf greats. "But any time you make a change, you kind of go back to being a beginner." In the midst of a swing change, a player's arousal levels are high: The brain is busy. Only when those levels are calmed -- and the player finds that he's swinging freely without pondering the positions of his body parts -- is the change said to have clicked.

But this, of course, is heinously elusive. Swing change or not, the thinking is always there in golf. The ball is stationary; the mind has ample time to consider such things as the many flaws in one's swing. Even great players must, at some point, make a leap of faith. They must believe. This is never more important than amid a swing reconstruction. "Because if you start doubting what you're doing, holy cow!" says Valiante. "That's probably what sends a lot of guys off the tour. All of a sudden they're playing with no confidence, and that's when you have an almost unfixable mess." The worst-case scenario: a partially ingrained bunch of new swing habits layered over the old ones.

IT WOULD BE almost two years after embarking on his swing change with Harmon, in May 1999, that Woods would call the coach from the range before the GTE Byron Nelson: "Butchie, I got it." Over the course of that season, he would win eight PGA Tour events. He would win nine more the next season, including a 15-stroke victory at the U.S. Open, the first of four straight major wins. He would, over a span of seven years, make 142 consecutive cuts, perhaps the most unbreakable record in golf. He would win four straight money titles. Five consecutive scoring titles. Harmon, at the time, would say of Tiger in the book Raising the Bar, "The mechanics have gotten so good. His set-up posture is perfect, the plane of his swing is perfect ... Everything about it is textbook. Some players get in a zone, play good for a while, but they never swing like Tiger's swinging now." When asked what, if anything, Woods might change, Harmon would reply, "The only thing I'd change right now if I were Tiger is the route I took to the bank."