NHL Commissioner Gary Bettman wrote the response to pseudo-scientific cranks in Congress that needed to come from Roger Goodell’s Remington-Rand five years ago.

“The science regarding CTE [chronic traumatic encephalopathy], including on the asserted ‘link’ to concussions that you reference, remains nascent, particularly with respect to what causes CTE and whether it can be diagnosed by specific clinical symptoms,” Bettman wrote Sentaor Richard Blumenthal. “In 2012, it was the consensus on medical experts on concussions in sports, including Dr. Robert Cantu (the primary expert retained by the players’ counsel in concussion litigation currently pending against the NHL, and a member of Boston University’s CTE Center) that a causal link between concussions and CTE has not been demonstrated.”

That remains true today. Researchers continue to create headlines by hyping individual case studies on famous players’ brains. But they fail to create any body of data establishing causation for CTE or its prevalence in athletic populations vis a vis society at large. A randomized study on CTE remains but an idea. Left with anecdotes, politicians and the press confuse speculation for science. They reach conclusions before a single study can examine the question.

Senator Blumenthal lauded the NFL when league executive vice president Jeffrey Miller cried uncle in May to badgering pols claiming an established link between football and CTE. The Connecticut Democrat wrote to Bettman in June characterizing the NHL’s response as “dismissive” and “disappointing.” But while the NFL temporarily got Congress of its back by yessing the politicians, the answer didn’t find the backing of any existing science. And when the league attempted to steer roughly half of its $30 million NIH grant toward such a study, Congress remarkably accused the NFL of tampering. Like Jim Zorn, Richie Petitbon, and Norv Turner, the NFL struggles to win in Washington.

Bettman’s smackdown of Senator Blumenthal demonstrates to the bigger league that reason rather than slick PR works best. Here’s Bettman at his best:

The confusion in the press about CTE—no doubt further fueled by plaintiffs’ counsel in the NHL litigation—relates to the simple and incontrovertible fact that none of the brain studies conducted to date can, as a matter of accepted scientific methodology, prove anything about causation, a primary subject of your letter. The disconnect stems from a failure to recognize the critical difference between brain pathology research (that is, looking for the presence of CTE pathology) versus the type of study required to demonstrate a causal link between CTE pathology and repeated concussive and sub-concussive impacts or any specific type of clinical symptoms in living persons. While an important beginning, a “case study” or “case series” of the CTE pathology (such as the research at Boston University’s CTE Center) can only show that a person who has died had what is now believed to be a unique “tauopathy” identified as CTE. But such a conclusion or finding does not speak to the subject of causation, the critical issue that must be addressed and resolved before proclaiming a public health risk. As various statements issued by medical experts studying the subject of concussions (noted above) demonstrate, in order to be scientifically relevant and reliable for establishing a causal link, studies must not only include a “control group,” but also must account for other illnesses, genetic differences and any other factor that may lead to the same pathology or clinical symptoms. In this respect, of course, we know there are millions of former athletes who played contact sports at the high school, collegiate and/or professional levels who show no persistent and/or continuing signs or symptoms of concussion injury or other cognitive or behavioral dysfunctions and who lead happy, productive lives. At bottom, the science just has not advanced to the point where causation determinations can responsibly be made.

And for people incapable of grasping reason, Bettman concluded his 24-page response (complete with 41 source citations and a bibliography) appealing to the emotions. He cited the case of Todd Ewen, an NHL enforcer who killed himself after suffering from depression. When doctors examined the brain that his family donated to science, they shocked his loved ones and many journalists by discovering no signs of the disease.

Bettman believes media sensationalism surrounding CTE unleashes psychological havoc on athletes retired from contact sports.

“This, sadly, is precisely the type of tragedy that can result when plaintiffs’ lawyers and their media consultants jump ahead of the medical community and assert, without reliable scientific support, that there is a causal link between concussions and CTE,” Bettman concludes in his July 22 letter. “Certainly, a more measured approach consistent with the medical community consensus would be a safer, more prudent course.”