Professional sports leagues in the United States have long relied on high schools to help cultivate the country’s best athletes. Rosters in Major League Baseball, the N.F.L. and the N.B.A. are filled with former scholastic stars, many of whom hold tightly to their quintessentially American memories of homecoming, letterman jackets and games played under the Friday night lights. But for the organization charged with producing soccer players who can compete with the world’s best, that system has been deemed inadequate. The United States Soccer Federation announced a new policy recently that will uncouple high school soccer and the training of top youth players, a move that is unique among major team sports in this country and, some believe, is indicative of a trend in the way the United States develops elite athletes. The shift by the federation applies to its top boys teams around the country, requiring players on those teams — known as Development Academy teams — to participate in a nearly year-round season and, by extension, forcing them and their soccer moms and dads to choose between playing for their club and playing for their school. The move has stirred a fierce debate among players, coaches and parents from California to Connecticut.