It is often said that there's nothing new in golf, yet the quest for knowledge in this most unconquerable of games has never ceased. While the most influential instruction has always come from the indelible techniques (and, to a lesser extent, the writings) of golf's greatest players, from Harry Vardon to Ben Hogan to Jack Nicklaus, it has been the teaching professionals who have best understood the methods of the masters and known how to convey the information so that beginners as well as experts can benefit. As the early teachers—Scottish pros primarily, men such as Alex Smith, who came to the U.S. to spread the gospel of golf to Americans like Walter Hagen, and Stewart Maiden, who was Bobby Jones's instructor—wrestled with the ever-shifting blend of art, athleticism and science that makes the swing so mysterious, their acolytes appropriated the best ideas, refining some and developing better theories themselves. And so it went, from generation to generation. As a result, there is a discernible lineage of the best thoughts on the subject, and those centuries-old concepts live on in the minds of players today.