This documentary about brain trauma in the NFL is largely anecdotal, but therein lies its power. Rebecca Carpenter set out to make the movie after her father, longtime running back and coach Lew Carpenter, died in 2010 and neurologists examining his brain tissue reported that he’d suffered for years from chronic traumatic encephalopathy (CTE). When a researcher shows Rebecca slides of her father’s brain, she can’t help but cry, and she begins to track down his old gridiron friends in search of answers. She presents a solid indictment of the league for its record of denial and delay, yet her movie is primarily the story of a grown child gaining a new perspective on her late father and their rocky relationship. Near the end, the medical issue lands on her doorstep a second time when her teenage nephew, who idolized his grandfather, sets out to win a football scholarship to college and follow him into the big leagues.