Sports are part of childhood, but concussion is a growing concern in the (very) minor leagues. Definitive answers about pediatric concussion, however, are proving to be a tough opponent, and many recent studies have underlined what researchers still don’t know. Some showed that the traditional approach of “cocooning”—a long period of bed rest after a concussion—may do more harm than good after the first few days. Others failed to find any threshold level of impact that consistently caused concussive symptoms. Some players experienced problems even without a “red flag” event on the field. For now, many of the complexities of concussion remain locked inside the skull.