Catcher Moe Berg earned his reputation as “the brainiest guy in baseball.” At Princeton, where he studied seven languages, he communicated plays in Latin with the second baseman, and he later attended Columbia Law School and the Sorbonne while reading 10 newspapers a day. After 15 undistinguished seasons as a ballplayer, he went to work as a spy during World War II, parachuting into Yugoslavia for the Office of Strategic Services and interviewing Italian physicists about the German nuclear program. (He chose not to shoot Werner Heisenberg.) His is the only baseball card on display at CIA headquarters.

Berg was awarded the Presidential Medal of Freedom in 1945, but he spent the last 20 years of his life living quietly with siblings. He declined to write a memoir, so much of his life is still a mystery. When asked why he had “wasted” his intellectual gifts on baseball, he said, “I’d rather be a ballplayer than a justice on the U.S. Supreme Court.” His final words were “How did the Mets do today?”