I recall liberal quips at Gerald Ford's expense, one of which was "He played too much football without his helmet on." Even four decades ago (pushing five, since the line was attributed to LBJ), folks had a handle on the idea that football could well mess with your brain, even if we didn't have the hard scientific data to back it up.
Eighty-seven of 91 former NFL players who donated their brains to science after death tested positive for a brain disease that is believed to be linked with repeated head trauma and concussions, researchers said.
The former players were found to have had chronic traumatic encephalopathy, known as CTE, according to the U.S. Department of Veterans Affairs and Boston University.
The one issue that I see in this one is a self-selection effect. Guys who were suffering from "having their bell rung" a few times too often, having various symptoms of CTE, are most likely to want to have their head examined after they died. Guys who didn't have those symptoms are less likely to go that route.
That's not to say that the CTE problem isn't real. It is very real, so much so that it's a good question whether we want to encourage that by spending large chunks of our weekend watching it.
However, the number implies that 95% of NFL vets have CTE. Healthy players, or ones who died of other causes (Reggie White dying of sleep apnea complications comes to mind) aren't in the mix as much. Thus, it might take a few decades for players whose conditions don't scream CTE to have their brains gone over after they pass on.