AGE: 38 OCCUPATION: President of baseball operations, Chicago Cubs

In only a few months, the former Red Sox GM has improved clubhouse culture (see the Carlos Zambrano trade) and coined a phrase—“the Cubs Way”—that stands for philosophical change on and off the field. Because Epstein has the power to assemble the player roster of tomorrow, the beloved but woebegone franchise will rise or fall on his decisions.

MORE ON EPSTEIN: Can Theo Epstein Deliver for the Cubs?

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Photograph: Phil Velasquez/Chicago Tribune