It would have been enough just to see them pitch. Taking the mound at San Francisco's Candlestick Park that summer night in 1963 were 42-year-old Warren Spahn and 25-year-old Juan Marichal -- the embodiment of an ageless wonder headed for the Hall of Fame and a whirling wunderkind making his own case for immortality. But as one scoreless inning followed another en route to a 16th-inning climax, the 15,921 fans in attendance began to sense that they were watching a pitching duel for the ages. They remained, shivering and thrilled, to see it end after midnight. The sui generis event surpassed the world of statistics and entered into the realm of magic.

Author Jim Kaplan, who covered baseball for Sports Illustrated in the 1970's and 1980's, initially planned to expand a magazine story he'd written about the game into book form. The more he researched the principals in his travels from San Francisco to South Buffalo to Santo Domingo, however, the more fascinated he became with their biographies. Spahn was one of the most decorated ballplayers to fight in World War II. Marichal narrowly escaped death three times. Despite their obvious differences -- Spahn was white, American, and left-handed, Marichal is bronzed, Dominican, and right-handed -- Kaplan found extraordinary similarities between the friendly rivals.

Listen in as Jim Kaplan takes us back, 50 years ago, to The Greatest Game Ever Pitched...