Ultimately, though, the threat to the NFL won't come from squeamish fans. It will come from a growing scientific body of evidence of the risk of playing football at any age, and from the parents who become increasingly aware of that risk. The NFL fully understands the danger this would pose. In one scene in League of Denial, neuropathologist Bennet Omalu, the first doctor to find CTE in the brain of a football player who had killed himself, recounts a private meeting he had with an NFL doctor.
"The NFL doctor at some point said to me, 'Bennet, do you know the implications of what you're doing?" Omalu replied that he did, but that the doctor should go ahead and tell him what he thinks the implications are. "He said, 'If 10 percent of mothers in this country would begin to perceive football as a dangerous sport, that is the end of football.'"