It’s one thing to be sidelined. But what if even the sidelines are off-limits? While business, politics and media have opened up to women, professional sports remain a much tougher game. Up-and-coming female coaches, like Phoebe Schecter, who runs NFL drills with the Buffalo Bills, are blazing a very narrow trail. Schecter is one of just six women in a field of 2,600, but programs like the NFL Diversity Coaching Fellowship aim to make those numbers meaningful. If male bastions like the military can open up, some argue, there may be hope for pro sports.