Get those hands up. After four weeks of play, running backs — not wideouts or tight ends — have been the primary pass catchers on seven NFL teams. What’s more, Cleveland’s Duke Johnson, Washington’s Chris Thompson and Los Angeles’ Todd Gurley lead their teams in not just receptions but in receiving yards too. That suggests a big change is afoot when it comes to the skills of recruited players. By season’s end, running backs could be the leading receivers on multiple teams for the first time in modern NFL history.