Does new science matter? Ask the NFL.  “A neuropathologist has examined the brains of 111 N.F.L. players — and 110 were found to have C.T.E., the degenerative disease linked to repeated blows to the head,” as described in a July 25, 2017 NYT article by Joe Ward, Josh Williams and Sam Manchester.  It’s an “interactive” story with various charts.

But, keep in mind selection bias is at work in this situation. As noted in the article: “The set of players posthumously tested by Dr. McKee is far from a random sample of N.F.L. retirees. “There’s a tremendous selection bias,” she has cautioned, noting that many families have donated brains specifically because the former player showed symptoms of C.T.E.”