Slow your roll here for a second. All of those 50 players are likely to be in their 70's now. I would contend that if you take ANY group of fity 70 year olds, you could find 8 affected with "cognitive imparement" and none would have played a violent contact sport for often over 2 decades. (between HS, Coll, and Pros)
Granted we all know that hitting your head in violent collissions over and over again is NOT great for your brain, but so is getting into your 70's. Now I know I'M don't have nearly the mental dexterity of even 10 years ago. But I have to question is that because of the 10 years I played football in my life, or is it the diabetes, or the heart disease....or just getting old.
Believe me, allowing your teenager to drive or be driven by another teenager is more likely to cause serious injury or death than allowing your kid to play HS and college football. But I don't see any ground swelling of support to raise the legal age to drive.
I just read where over 700 mothers in America die each year due to preventable complications in child birth, thus giving the US the highest death rate in the entire industrial world. I know I'm ranting now, but I'm just making the point that there is more outrage about eight 70 year olds who are having some cognative issues, than about 700 preventable deaths per year in childbirth.