The notion started taking shape for Lee Trevino at the Bay Hill Classic this month after he took The Eleven.

Standing in the sixth fairway, 200 yards from the green, Trevino decided to hit the shot that has made him the second-leading money winner in golf history-the controlled fade.

Instead, his long iron hooked into a lake. He dropped another ball, then hooked it into the drink, too.

"I was not by then," he said, recalling the moment. "I dropped down a third ball and I finally managed to fade one. Of course, I also bladed it. It skipped five times before it sank. I counted.

"When I got to the green, I stood there like a 30-handicapper counting up the strokes on my fingers. I ran out. I thought I'd made 12 . . . it was only 11."

That was enough. Trevino quit the tournament after that round. "I'm no 78 shooter," he said now. "I had to figure out what was wrong."

What he finally decided was, "Here I've been trying to hook the damn ball for two years after I made all that money ($1.9 million) fadin' it. Who'd have though I was that dum . . ."

After all, it was the "Merry Mex" who invented the expression, "You can talk to a fade, but a hook just won't listen."

There was, of course, a reason why Trevino switched his game around from 1976 to '77 developing a low draw. He was struck by lightning. In the aftermath of the terrifying accident, Trevino developed back miseries that required surgery. The 5-foot-7 hustler lost considerable power, the commodity he could afford to lose least.

It became Trevino's workaholic obsession to prove that, just as he had beaten poverty in his youth, he could beat lightning and major surgery in his athletic old age.

He hung upside down in a back stretcher for frightening lengths of time each day and exercised enough for a corps of marines.

After eight straight years in the money-winning top 10, Trevino slipped to 13th in '76, then 33rd in 1977 after the lightning incident. Trevino's adoption of the "old man's hook" for extra roll was his answer to all his physical ailments.

Last season, Lee the Hooker won $228,723-only $3,000 less than he had won in '71 when he was PGA player of the year by acclamation. His sixth-place finish on the money list was one of the sports comeback stories of the decade, although a surprisingly little-noted one, probably because Trevino made his money with five second-place finishes, not with prestigious victories.

Now however, Trevino is back at last, feels "100 percent again." Just a few months before his 40th birthday, Trevino has set out on a campaign that perhaps only a golfer could dream about. In jockdom's middle age, he is completely restructuring his game, trying to go from the comfortable Top 10 to the very top where he once cavorted.

"No one can hit both a fade and a hook with consistent control of both. Basically, you have to depend on one 'shape' of shot," said Trevino, "'cause nobody can hit it straight every time. You gotta choose."

So, Trevino, still perhaps the most genuinely funny man in sport, has turned back his personal clock-not with quips but with sweat and study.

"I got out my old stiff-shaft irons . . . the ones I won everything with," he said, relishing the words. "I didn't even have the six-iron any more . . . I'd given it to some museum, so I had to get a new one.

"I got out the films of the last shot I hit in the '71 British Open to beat Jack Nicklaus-the eight-iron that ended up three feet behind the hole."

Not a stack of films, mind you, just one of a cruscial swing-probably the best pressure swing of his clutch career. Trevino has looked at it a hundred times.

"I've noticed several little thing," he said. "For instance, then the cleats of my left foot never moved off the ground at any time . . . I was planted, rooted. I started lifting my heel when I had back problems, trying to get a fuller turn for more distance."

This transformation-this reversion to the true Trevino-only began one week ago. Trevino has been smashing 300 or more balls a day, practicing the way he once did as a scuffling public-course driving range instructor who didn't join the tour until he was 27.

"That used to not be a lot of balls for me to hit, but I'm gettin' old now," he said, beaming, obviously thrilled as a kid with a toy at the prospect of rebuilding his game from ground zero.

Trevino has created for himself a special set of rules. "I'm a fiddler and a changer," he said. "I got 100 putters and 100 wedges at home, I put tape around 'em all so I couldn't start pickin' up one after the other and saying, 'That feels good. Think I'll use it today.'

"At Bay Hills, I used three different sets of clubs in three days. That's got to stop. It's bad enough that I'm still using four different swings out there now."

Even Trevino has been shocked at the suddenness of his improvement.

His 70-69-139 start left him in third place at the midpoint of the enormously difficult Tournament Players Championship have.

"I'm still doing a lot wrong," he said. "I've neglected my short game. I'm even leaving 10-foot putts short."

However, he is doing a great deal more that is right. Trevino can still hit the low wind-cheating wedge that stops on a dime like no one else ever has-"scald it and skid it," he said. His drives-hook or fade-have always been the most accurate on tour.

Now his irons, the clubs most cursed by his hook, have responded. "The bad part of fading all the irons is that you can never fire at the pin when it's tucked left," he said. "You can only get close when it's in the middle or right.

"The good part is that you never hit to the wrong (narrow) side of a green . . . you never leave yourself an impossible chip when I was hooking and fading, I was all over the place . . . making bogey." He curls his lip at the five-letter obscenity.

That word is verboten to Trevino. The hallmark of his game is a dogged succession of pars seasoned with occasional birds. "If you make bogeys against Trevino," said protege Lon Hinkle, "you go home without your wallet."

It is true that Trevino's quips are brilliant, salty, and spontaneous-creations he almost never repeats. It is equally true, but overlooked, that he is one of the game's greatest fighters-watch his bared, gritted teeth as that "scald and skid" wedge burns toward the stick. That is no joke.

Trevino's heroes are the little cut-your-heart -out battlers who walk home with the cash.

"I never spend any time with golfers away from the course," he said, proudly and revealingly. "I don't wanna hear, 'At seven, I hit it 20 feet over the green.' After 6 p.m., I charge caddie fees to listen.

"You can count the guys out here (on tour) on one finger that I've had dinner with in 12 years," said the gregarious Trevino who, in this respect, is fiercely antisocial.

Trevino has the ancient caddie-yard ethic: "pay to learn." That is. open up your wallet head-to-head after hours and let's see who wins. "You wanna see somebody play hard for $2?" said Trevino with a grin, "it's that Gary Player.That crazy man will start linin' up six-inch putts from both ends for a $2 nassau. It's just his pride. And pride in what you do well is what makes a man."

That pride, not mother wit, is what separates Trevino, makes him special, allows him to beat lightning, surgery and age. True, he can't play anymore unless the weather is warm. "I won't even get milk for my daughter at the corner store when it's cold." And he claims his putter is learning to yip. "I get to coughin' and leakin' over those short ones," he said.

But the thought of getting out the old clubs, the old movies and the old swing as he approaches 40 does nothing but inspire Trevino.

"I'm tryin' to find my game, but I'm not tyin' to find myself," he said sharply. "I've known who I was all along. If I forget, I look at my driver's license.

"I'm not one of these freaky cats, sayin', 'Hey, man, where are you coming from?' and 'Where's it at"'

"I've always been 'at' the same place."

And where is that"

"Right here," said Trevino, a philosopher of two words, stomping his proud little foot on the firm earth. CAPTION: Picture, Lee Trevino: "You can talk to a fade, but a hook just won't listen." AP