Sometimes the numbers say it all.
A newly published study on the impact of American football found that 110 of the 111 NFL players who donated their brains for research suffered the condition chronic traumatic encephalopathy.
The survey might be skewed somewhat by the fact that those donating their grey matter are possibly more likely to suspect they have suffered the condition.
So let's be generous and say that you have a one in 10 chance of finishing a career in the NFL without suffering a condition with symptoms that include memory loss, confusion, impaired judgment, aggression, depression, anxiety, impulse control and sometimes suicidal behaviour.
Welcome to the NFL, son. Check your brain in at the locker-room door.
Even allowing for the now long-running battle between CTE sufferers and the NFL, which has literally billions of reasons to bury its head in the sand, the proportion of boggled minds — 99 per cent of those studied! — is mindboggling.
According to the study this put the NFL in the same category as war veterans. So in a way never envisioned by the sport's endless battle analogies, the NFL is sending its players to war.
The survey resonated in Australia. We are belatedly embracing the idea that concussions once viewed as an incidental consequence of our robust games can have life-changing, even life-ending, consequences.
The sickening sight of the Melbourne Storm's Billy Slater knocked out cold after a brutal hit, and the judiciary testimony that he could not remember anything that happened in the last two weeks, was just the latest example of why we must protect the head. Not just make hollow promises to do so.
Thankfully, the referees and bunker officials who failed to send Canberra's Sia Soliola from the field after he struck Slater were universally ridiculed; not lauded for perpetuating a folklore that mistakes brutality for masculinity.
Yes, the damage had been done. But in a game where incident contact is inevitable, prevention of deliberate acts by threatened punishment is even more vital — even if, in this case, it was not particularly well enforced by the lenient five-week suspension Soliola received.
But change is coming, if all too late for those disoriented and disillusioned ex-footballers whose only recourse is a Hail Mary law suit or to donate their brains to science hoping others won't suffer as they have.
This week, the AFL Rules Committee discussed providing a concussion substitute for teams that lose players to the condition during this year's finals. This change would, at least notionally, encourage teams to bench concussed players rather than keeping them in the fray.
But while we modify rules, impose more stern punishments and test protective equipment, there is one question no one asks: If you see someone hitting his head on a brick wall do you give him a helmet or do you make him stop?
We don't ask this question because in our sport in its present form, as near as possible to it, it is considered a given. Nothing — not even the certainty that some of the heroes we cheer on each weekend will suffer debilitating brain injuries — will prompt this kind of introspection.
But if we can't countenance the idea of abstinence as a solution to the most traumatic injuries in professional sport, then how do you reconcile this with children? Yes, your children!
The same survey that found 110 of 111 NFL players revealed 48 of 53 college players and three of 14 high school players suffered CTE.
Is 'resilience' enough of an excuse?
NFL with its brutal helmet first bayonet charges is more prone to head injuries than most, if not all, sports. But Australia's various football codes cannot, and thankfully are not, pretending to be immune.
We will never stop our children banging their head into that metaphorical brick wall. The benefits of sports — we hope and trust — well and truly outweigh the risks.
The greatest defence of the robust nature of sport for children particularly is that modern buzz word, resilience.
Put children into uncomfortable and even physically confronting situations, we tell ourselves, and they will build the stamina and fortitude to confront some of life's greater real-world challenges.
Sport is full of conceits and self-justifications. But as a parent and junior coach, I think there is some merit to this argument as long as the challenges are calibrated to provide a reasonable test of each individual. Too often, junior sport merely divides the most and least physically able.
The old-timers who moan about the disappearance of scoreboards at some junior games and modified conditions will tell you we are going too far; that rules designed to provide physical and emotional protection for children are ''political correctness gone mad''.
But we are now confronted with unequivocal evidence of the impact of cumulative traumatic injury.
Football was once considered a safe haven by the Soccer Mums. But turn the page in any medical journal discussing concussion in sport and you'll find a study showing that heading the ball is a likely source of irreparable brain damage.
Cricket had seemed the most benign pastime. Yet the devastating Phillip Hughes tragedy resonates throughout the game. In local clubs the compulsory helmet rules was once derided as a nanny-state imposition by old-timers. Now we know a helmet is not sure-fire protection against a potentially lethal short ball.
The NFL survey is the most extreme example of sport's greatest dangers. But next time you ridicule a junior official for ''making the game soft'', remember those chilling numbers and the fact that everything starts somewhere.
For more on the implications of the NFL concussion study watch Offsiders with Gerard Whateley at 10am Sunday on ABC TV.