Money and rugby have always been an explosive mix.
Cash for players split the game in two in England in 1895 and led to the invention of rugby league. Bizarrely, it took World War II and the spirit of unity after Europe's victory over Hitler to halt a moveto kick France out of the international game because their club players were getting what was called "boot money" before matches.
We now know that world rugby faces a crisis over concussion and long term effects on the brain that common sense suggests have been exacerbated by rugby becoming fully professional in 1996.
The game of rugby itself has changed dramatically. Many of the developments are for the good. Skill levels now are astounding. As a prime example, taking high kicks by leaping in the air was once the preserve of a tiny, gifted group. Now it's a standard skill for provincial fullbacks and wings.
The norm for fulltime professional players is to spend hours honing their skills. But in the distant past it was considered weird that, for example, a great wing of the 1950s, Ron Jarden, while studying at Victoria University in Wellington, would spend 90 minutes every weekday morning training by himself at a local park. He'd clock up hours running down the touchline until he could consistently centre kick the ball onto a spare jersey in the middle of the ground.
Today the skill sets of most All Black forwards would match many backs from the amateur days.
But it's hard not to feel that spending so much time training is a double-edged sword.
Rugby should look to boxing - a sport where, in professional bouts especially, the basic aim is actually to inflict concussion on an opponent by knocking him or her out - for hints as to where the sort of brain damage is caused that can have catastrophic consequences, of the kind that were revealed this week by Dylan Cleaver's stories in the Herald.
It's natural to think that most harm to a boxer occurs when he or she is knocked unconscious. But there's much research that strongly indicates time sparring in the gym, for years considered harmless, may be even more devastating to a boxer's health than what happens in an actual fight.
In 2015 a Melbourne doctor, Peter Lewis - involved with boxing for decades - and his colleague Dr Michael Wang, wrote in a paper for the "British Medical Journal" that "sparring was a problem, with most of the trauma contributing to brain damage sustained in training rather than in fights. It was important to educate trainers and fighters about the need to go lighter in sparring sessions and dispel the myth fighters could be 'hardened' by heavy sparring, which would reduce head trauma."
Last year researchers from the University of Stirling in Scotland tested the motor control and brain function of 20 amateur boxers following a nine-minute sparring session.
The fighters were tested before and after sparring and again one hour and then 24 hours later. The researchers discovered that fighters performed 52 per cent worse on memory tests immediately after sparring, although brain function did return to normal 24 hours later.
Don't be lulled by the memory recovery into believing no harm had been done.
"Although transient, we found brain changes observed after sparring are reminiscent of effects seen following brain injury," said lead author, Dr Thomas Di Virgilio. "Our findings are important because they show routine practices may have immediate effects on the brain."
In rugby we wince watching high tackles go wrong in a game, and tackles above the waist to prevent offloads are now largely the norm. The number of tackles professional players make, as defensive lines now rapidly spread across the field, has also vastly increased.
But the reality increasingly looks to be that as tough as referees get on high tackles, the hours spent by professional players in body contact training, whether tackling, scrummaging, or working on breakdown techniques, may be where the most essential changes need to be made.
Amateur rugby took some horrific risks with player safety. As a teenager in 1965 I witnessed how ridiculous the rule was that, in games involving an international team, no injury replacements were allowed. It allowed a New Zealand Universities side to be reduced by injuries to just 12 men for the last 30 minutes of a match against South Africa at Eden Park. The nadir was reached when NZU halfback Chris Laidlaw was allowed back on the field, tried to drop a goal, and then fell unconscious to the ground.
Concussion then was considered something real men rose above. Groggy players would be splashed in the face with water, and lurch back to their positions.
There are no excuses now for ignoring concussion on the field. But for rugby to progress in the 21st century that concern must also embrace the training ground.