The late Bobby Jones once said that when he died he expected to go to heaven, and he hoped there would be a golf course there. If so, he reckoned, it would be like the Old Course at St. Andrews.

To purists who think golf should be a supreme test of the mind as well as of shotmaking technique, this most ancient and famous of all links is a bit of heaven carved out of the windblown sandlands on the east coast of Scotland where the North Sea forms St. Andrews Bay.

To the impatient, fainthearted souls who cannot cope with the whimsical kick off the mounds on the fairway, the heartbreaking bounce or the unseen hazard, the Old Course is Hell, which is also the name of its crulest and most famous bunker.

Skill and stoutheartedness, thoughtful adaptation to the conditions of the moment an d strenth of character will all come into play in deciding the 107th British Opens Championship, which begins today over this 6,933-yard, par-72 museum of golf.

Jones, who won the second of his back-to-back British Opens at St. Andrews in 1927, was unimpressed by the Old Course when he first saw it. He though it looked easy, but he could not score well on it - a paradox that often has confronted accomplished players on their first acquaintance, before they realize there is hardly a level stance on the entire links.

Gradually, Jones came to appreciate the charm and eccentricities of the course, to love it, as the best golfers of many generations have, as a unique and demanding challenge.

"I could take out of my life everything except my experience at St. Andrews," he said decades after his first encounter, "and I would still have a rich, full life."

Humps and hollows, hills and depressions, devilish traps and enormous, undulating double greens - one of which covers more than an acre - are hallmarks of St. Andrews. So are the scores of pot bunkers, which Bernard Darwin, first of the great golf writers and historians, once noted were "big enough only for an angry man and his niblick."

"Hell," which along with "Kitchen." "Grave" and "Ginger Beer," guards the approach to the 567-yard 14th or "Long Hole," is the best known of the numerous and personalized bunkers. It was on emerging from its forbidding, sandy depths that one unfortunate chap of long ago was asked by his playing partner. "How many?" To which he gave the often-quoted reply: "I went in at a quater past 12, and now it's a quarter to one. You can make your own estimate."

Less legendary, but just as aptly named, are the bunkers called "Coffins," "Cat's Trap" and "Lion's Mouth." Also well known are "Beardies." "Elysian Fields" and the cluster of small, treacherous traps referred to in the aggregate as "Principal's Nose."

Some of the other bunkers are named after people - "Kruger" and "Mrs. Kruger," to name a couple, and "Walkinshaw's," so called because a local fellow of that name came to find his way into it no matter how many different ways he tried to avoid it.

There are other noteworthy lankmarks on the Old Course: "Granny Clark's Wynd," a roadway that runs from town to the beach known as "West Sands," via the first and 18th fairways; "Swilcan Burn," a stream that cuts across the same two holes, and "The Valley of Sin," the troublesome dip in front of the 18th green.

Gorse, heather, tall grass and tangled underbrush make for ungodly roughs. The bunkers, some of them lurking out of sight if not out of mind, are constant hazards. Trouble looms to the right of nearly every fairway, even on calm days. And when the wind blows, which is most of the time the cradle of golf really rocks.

Andrew Fyfe, a weatherbeaten man of 77 with a goat-like countenance and tuft of snowy hair on his chin that makes one understand perfectly how the word "goatee" originated, is a steward on the 461-yard 17th, celebrated as the "Road Hole" because of the 18-foot wide stretch of pavement that runs along its right boundary, past the Old Course Hotel. He was talking about the winds during yesterday's final practice rounds on a chill Scottish afternoon when the skies were the color of oatmeal.

"I stood out here all day Monday and shivered, it was so cold," he said. "That is when the wind blows from the east, off the North Sea. But when the west wind blows, it's worse. It's a gale. And you have crosswinds all the time, always changing. That's what makes it so difficult."

Because the breezes can be expected to whip up from time to time during the four days of the Open, the odds favor a low, straight hitter who can stay out of trouble.

"You just got to bump it and run it in," said Lee Trevino, who arrived here Monday after losing the playoff to Lee Elder on the eighth hole of sudden death at the Greater Milwaukee Open Sunday. He was exhausted and went straight to bed, but he played a full round yesterday afternoon and practiced well into the long Scottish evening.

"I think my game is suited to this kind of course because I keep it low and like three-quarter shots rather than full ones," said Trevino, the champion of 1971 and 1972.

He recalled that he three-putted the vast expanses of green here six times during the last round in 1970 after holding a two-stroke lead at the end of three rounds. "I hoe St. Andrews owes me something," he said.

As his dark horse pick, Trevino selected Andy Bean, who has won three of the last five tournaments on the U.S. tour and is playing his first British Open. "He hits long and straight and keeps the ball low. You'd think that a fellow 6-4 wouldn't have much trouble getting the ball up in the air, but he does and he's playing awfully well right now," Trevino said.

Trevino and Bean are two of 28 Americans in the field for this oldest and most internationally revered of golf tournaments. Among the others are Jack Nicklaus, winner in 1966 and 1970 and six times a runner-up; Tom Watson, who won at Carnoustie in 1975 and outdueled Nicklaus in a 36-hole showdown at Turnberry last year; 1973 champion Tom Weiskopf, 1976 champ Johnny Miller, Hubert Green, Ray Floyd, Mark Hayes, Jerry Pate, Lanny Wadkins and Hale Irwin.

Arnold Palmer, who lost by a stroke to Australian Kel Nagle in the Centennial Open here in 1960, then won the next two years, is little more than a sentimental favorite in his 19th consecutive British Open. After a spirited practice session, he had some observations about the Old Course.

"It has more subtleties - some players have other words for it - than almost anywhere else we play," he said. "No one would build a course like this today, but it is a magnificent links that takes a great deal of thought to play. It is vitally important to put the ball where you want it off the tee.

"This is about the only place I know where you can get a blind putt," Palmer continued, referring to some greens that cover hills and dales and look strangely like grassy cliffs. "But the real problems are the bunkers, the undulations in the fairways and the weather."

Those are the things that St. Andrews, the birthplace of golf, is all about.