In February, Josh Begley, a San Francisco native and Cal graduate, finished producing one of the most haunting short films of 2018.

About the series
For years, mounting evidence has linked football violence with brain trauma and life-threatening conditions. Now that we know the sport can produce deadly results, where do we go from here? The Chronicle offers this special report on The Future of Football.

For more than five minutes, viewers are presented with stitched-together footage that includes stretchers, motionless bodies, thousand-yard stares and high-impact collisions that result in flying spittle and, on one occasion, a pair of trembling, locked arms that suggest a seizure.

Begley’s film, “Concussion Protocol,” is a compilation of every reported concussion from the 2017 NFL season. An avid football fan who increasingly struggles with the game’s violence, Begley wanted to create a historical record of the carnage to which many fans have become desensitized.