In 1964, the Cubs traded outfielder Lou Brock to the Cardinals for pitcher Ernie Broglio. It became one of the most lopsided trades in baseball history, as Brock went on to have a Hall of Fame career with the Cardinals while Broglio’s career fizzled out almost immediately.
In baseball lore, it might not be up there with the Red Sox selling Babe Ruth to the Yankees, but that trade epitomizes the opposite fortunes of two of baseball’s most storied franchises. While there were obviously other factors at play, the Brock-for-Broglio swap stands as turning point in the Cubs/Cards rivalry.