About Concussion Watch

Every week in the National Football League, a player is sidelined by a head injury. In some cases, their symptoms are clearly visible and they exit the game. Other times, less obvious warning signs can mean a missed diagnosis and a return to the field. Either way, research indicates that the long-term health effects of such injuries — including memory loss, depression and even dementia — can pose problems for players long after retirement.

Starting in 2009, the NFL was taken to task in a series of congressional hearings for its refusal to acknowledge that players could face dangers posed by concussions. The league has responded by adopting new rules designed to better protect players, and by stepping up outreach to show it takes the issue seriously.

Concussion Watch is an effort to monitor the NFL’s response to the persistent risk of head injury in professional football. To do so, FRONTLINE will track which players are being removed from games after a hit to the head — and which players are not — and keep score of how long they are kept from the field following a concussion.

The players included in Concussion Watch are those who have officially been listed on the NFL injury report with either a concussion or a head injury beginning with the 2012-2013 NFL season. The project is part of FRONTLINE’s ongoing coverage of the NFL’s concussion crisis, which includes the 2013 investigation, League of Denial.