Bestselling author and former Kansas City Star columnist Joe Posnanski discusses his new book about the most remarkable rivalry and (eventual) friendship in modern golf.

The first time they met, at an exhibition match in 1967, Tom Watson was a 17-year-old high school student and Jack Nicklaus, at 27, was already the greatest golfer in the world. Tom revered Jack. Jack barely knew who Tom was. But over the next 20 years they battled again and again for championships, a place at the top of the sport, and the title of greatest living golfer.