I've used these 6 fundamentals throughout my career. They'll help you reach your potential.Editor's note: The first article by Jack Nicklaus that appeared in this magazine was in the February 1963 issue. Eight months earlier, Nicklaus had won his first major championship as a professional, the U.S. Open at Oakmont, and already the editors knew he offered something truly special. "This 23-year-old not only has an amazingly mature knowledge of swing fundamentals," they wrote, "but also the veteran professional's ability to incorporate them into his own game."As we celebrate our 70th anniversary we again turn to Jack, now 80, to explain the full-swing fundamentals he used, along with his long-time instructor Jim Flick, to win his major championships and more than 100 titles in total. Jack's timeless principles can help you save strokes and improve your game. —Roger Schiffman