In late November 1964-seven months after Arnold Palmer won his fourth Masters title on an idyllic spring day with 40,000 patrons in attendance at Augusta National-he and Jack Nicklaus played 36 holes in a cold rain before a smattering of fans in Lafayette, Louisiana. For Palmer and Nicklaus, the stakes at the backwater Cajun Classic could not have been higher. It was the last PGA Tour event of the season, and Palmer led Nicklaus by a mere $318.87...