More than a year ago, the USGA began surveying fans, players, volunteers, sponsors, representatives of host courses and media members to identify key attributes that uniquely define the championship. Many of them are familiar to knowledgeable golf fans: The U.S. Open is seen as the toughest tournament in the world. It’s also one that’s uniquely open to any top amateur or professional who wants to enter. It’s played on America’s greatest courses. And its run by the USGA, a point that seems obvious but isn’t always understood by casual golf fans. (Yearly USGA research says that only 20-30 percent of fans understand who runs any of the four majors.)