One of the most distinctive movements in golf, it has been called the Mickey Mantle follow-through, after the famous Yankees baseball star. With his right arm finishing low across his chest, Justin Leonard has made a special impression on the tournament scene this season, not least by capturing the British Open at Royal Troon last July.

It has been said that Leonard's swing reflects his overall approach to the game - straightforward and uncomplicated, but with a dash of boldness. And his strong suit is balance, both in the execution of golf shots and in a cool mental approach to the business of handling his newfound fame.

According to his one-time coach, Randy Smith, Leonard remains pretty much the same golfer that came for lessons as a 10-year-old at the Royal Oaks Country Club in Dallas, back in 1983.

"Because he was so small, Justin couldn't carry the ball 130 yards with his driver at that age," recalled Smith. "But then, as now, he was a mature thinker who beat the opposition with smart course management, patience, concentration, discipline and playing the game one shot at a time."

Most of these virtues were in evidence at St Andrews recently, when he competed for the US in defence of the Alfred Dunhill Cup. Indeed he gained the distinction on the opening day of setting a record 65 for the lengthened, so-called Millennium Course.

Leonard is one of the new breed of American players. With Tiger Woods, Phil Mickelson and Jim Furyk, he was among the twentysomethings who were supposed to regain the Ryder Cup at Valderrama in September. And they will be spearheading their country's hopes once more, at Brookline, in 1999.

As we sat down to talk, I had with me the mental image of a remarkably composed 25-year-old holding aloft the famous claret jug in his moment of triumph at Troon. And whatever should happen this weekend in the USPGA Tour Championship, his last official assignment of the season, it will have been a memorable 1997 for a richly gifted player.

"I can remember most everything about Troon," he said in a soft, Texas drawl. "I didn't have a victory speech prepared, but the press secretary with the R and A gave me some note-cards with names, like the R and A captain, the course superintendent and things like that.

"He had also written down the name of Barclay Howard (the leading amateur), whom I remembered from the Walker Cup. Then, once I got past the names that I didn't know, I put the cards in my pocket and just talked about the things I felt had made the tournament special for me, personally.

"You know, things like getting to play the final round with Fred Couples and the great tradition of the British Open. It's still very fresh to me, all the more so for being here at St Andrews, where I made my first appearance as a professional in the British Open two years ago."

Watching his intense, young face with not even the hint of a smile, it struck me how seriously he took his golf, perhaps life in general. Leonard went on: "Being here in this atmosphere, playing such a famous links, brings everything back, crystal clear.

"And in terms of my development as a golfer, it's very important to be in this part of the world, playing in adverse conditions. To be considered world-class, I believe you've got to be capable of competing in hostile environments. That's our goal."

With a final round of 65 at Troon, Leonard came from five strokes behind the third round leader, Jesper Parnevik, to win by three from the Swede and Darren Clarke. It was a comeback that had previously been accomplished only once - by the English-born, adopted American, "Long" Jim Barnes, in 1925.

Wearing a baseball cap bearing the Hogan logo, Leonard had produced a round worthy of the most famous golfing Texan of them all, the player they called the "Wee Ice Mon" when he captured the title at Carnoustie 44 years previously. The manner of his play of three critical holes certainly bore the Hogan stamp.

By single-putting the 15th, 16th and 17th, one for a par and the other two for birdies, Leonard effectively placed both hands on the coveted trophy. "The hair on the back of my neck stood up," he said, after the 30footer found the target at the short 17th. He was the same age as Tom Watson had been when he won the first of five British Open titles in 1975.

I put it to him that, on first playing St Andrews, Bobby Jones hated the course so much that he tore up his card. The mask never slipped. "I can't speak for Mr Jones," Leonard replied. "I can understand why people consider the Old Course to be unattractive and unpredictable, because of the bounce of the ball. My response is that that's the beauty of it - not knowing where the ball's going to end up."

And what of the placement of the bunkers, which seem to be random, rather than strategic? "Yes, but they're very much in play," argued this golfing graduate. "It's not like there's a couple of bunkers out there that you can simply blow the ball over, downwind. Because there's always another one waiting to trap you. I'm amazed to see how well the course stands up to all types of conditions."

Different from the target-type golf to which he is used? "It's very different from what we play in the US, which can sometimes become a little monotonous," he replied. And once again, there was an anxiety not to offend anyone back home, as he added: "Don't get me wrong, we play some really good golf courses. But here, you have to use so many kinds of shots, so different from what we play in the States.

"I was small growing up and I had to bounce the ball into the greens and play different shots to compensate for my size. Now, as a professional, I really enjoy coming over here and using those shots as a natural part of the game."

Those of us who were at the Walker Cup at Interlachen in 1993 considered it something of an honour that an Irishman, Raymond Burns, had the distinction of facing Leonard in the opening singles. Burns had reason to think differently, however, after losing by 4 and 3. "I thought I was a good player until I met this guy," he remarked.

When I informed Leonard of the remark, he didn't demure. "I was more mature than most of my contemporaries," he said. "There were a lot of guys out there at college level who hit the ball better than I did.

"In fact, in that Walker Cup team, I was probably middle of the road as far as ball-striking was concerned and was definitely a short hitter. But I knew how to get my game around the golf course and I was a good match-player. I didn't let things bother me. That's probably what set me apart from the other players."

It certainly did. Apart from winning the highly competitive Western Amateur twice, he captured the US Amateur in 1992. Two years later, shortly before turning professional, he won the NCAA Championship with a 17-under-par aggregate of 271, to equal the record set by Mickelson.

More recently, he became one of the last of the leading US tournament professionals to use persimmon, which he eventually abandoned last May. "This titanium driver (which he declined to identify) is the first one that gave me the sort of control I could feel totally comfortable with," he said.

"Now that I've achieved a great deal of success with it, I don't see myself changing. I believe I'm hitting my drives 10 to 15 yards further. The statistics probably won't show that, but after playing these golf courses, I know I'm hitting it farther."

HAD he thought of broadening his knowledge of links terrain through a visit to Ireland? "I haven't been to your country but I'd love to," he replied. "To be honest, I'm not familiar with your courses - I'd have to study up a bit. But one of these years, the week before the British Open, I will come over with my father and start my preparation in Ireland.

"Ideally, I could play a few courses there and then a few more over here. Five or six days in all. But before doing anything, I will speak with Tom Watson, who seems to know every course in these parts. I know my father would love to do it too. He's useful, off seven or eight handicap, and can shoot 80 or 83. Those type of numbers."

At this stage, I became aware that Leonard's compatriot, Brad Faxon, had been sitting close-by throughout the interview, saying nothing but listening intently. I concluded that he was looking out for his young colleague, in view of controversial comments made in the British tabloids during the Ryder Cup.

Leonard seemed to be eminently capable of looking after himself, however, as he went on to talk of the golfers he admires most. "I've gotten to know Bryon Nelson a little bit over the last three or four years and I admire him a great deal," he said.

"He seems to look after me a bit. For instance, a few years ago, when I hadn't been playing well for about three or four months, he pulled me aside and sat me down for about an hour and just talked about the things I was trying to accomplish. He made suggestions as to how I might change my approach to getting there.

"We're not talking technical help, but he's had so many great experiences in his own career and he remembers them all. Astonishing memory. Like he would talk about an amateur matchplay tournament he competed in when he was 17 and recall not only his shots but the shots his opponents played. And we're talking about more than 60 years ago. I find that amazing."

And Hogan? "I met Mr Hogan on two occasions but I didn't really get the chance to talk a great deal with him. I'm astonished at what these players accomplished and I have made a point of reading up on them. Very much so. I know Mr Nelson on a more personal level, so I look up to him for the way he treats people and what a great citizen he is."

At this point, I couldn't help thinking of the first tee at Oak Hill two years ago, when each Ryder Cup competitor, American and European, was introduced to Nelson before starting their singles match. Had he been at Valderrama, could the great man have altered the outcome of Leonard's match in which Thomas Bjorn got an unexpected and crucial half-point? A fascinating thought.

Finally, I asked him the cliched question as to which three people, alive or dead, he would most like to invite to dinner at his local golf club. At this, Faxon stood up to leave, smiling - "I'll make it easy for you not to pick me."

Leonard laughed. Then, serious once more, he replied in typically measured tones: "Byron Nelson, Ben Hogan and my father." And it struck me that here was a young man who clearly knew what he wanted out of life.