This was at a time when tennis was more consciously a three-cornered marriage of sport, theatre and One Flew Over The Cuckoo's Nest. Jimmy Connors took behaviour to unheard-of lows, before John McEnroe took it even lower. Ilie Nastase took it to places of his own curious invention.

Kyrgios's tantrums, like much else, seem like pale imitations of that great unhinged time, and he doesn't have and never will have the influence of those great players. He is more of a curiosity at this stage of his career, which takes us to The Volcano.

The Volcano was one of the great unfulfilled talents of the Paleogene period. He played McEnroe throughout their youth and rose to world No.21, winning the New South Wales Open and overcoming such storied names as Brian Teacher, Chip Hooper, Johan Kriek and Kim Warwick.

At 195cm and close to 100 kilos, Buehning was likened to a bear. His father Peter was a champion gymnast for West Germany and his mother Renata represented the USA at handball. His brothers Peter and Jim both represented the USA in handball at the Olympics. But Fritz was the family's star.

His Achilles heel turned out to be his Achilles heel, but before that, it was his temper. Even as a champion 14-year-old, Buehning was up for a fight. In one junior match against notorious hothead Brad Gilbert (later coach of Andre Agassi and Andy Murray), self-umpired by the players, Buehning caught a serve that had landed in the middle of the box and called it out.

When Gilbert protested, Buehning said, 'If you keep giving me bad calls at your end I'm going to give you bad calls at my end.' Gilbert chucked a wobbly.

His next serve, Behing caught again and called it out again and threatened to keep doing it until Gilbert played fair. McEnroe said The Volcano was one of the most talented players he knew but, "like me, Fritz wore his heart on his sleeve and played the game with a lot of passion".

When he went off, The Volcano could wipe out the dinosaurs. Although he admitted his outbursts were directed at himself, he usually managed to divert them towards officials. In one match against Vitas Gerulaitis, his screams so terrified a lineswoman that she asked to be removed to a safer place.

Buehning claimed to be second only to McEnroe in the number of fines received at Wimbledon, which was some achievement considering McEnroe won it three times and made the second week 11 times, whereas in his six-year professional career Buehning never reached the second week once.

"It's ironic," Buehning said of his Wimbledon eruptions, "because to me Wimbledon is the mecca of tennis."

He had another similarity to Kyrgios: he didn't work as hard as others. His contemporaries, who knew how good he could be, were mystified that Buehning didn't follow the fitness trends in the game. Recognising his problem, he went to Harry Hopman for coaching, and another Australian coach, Bob Brett. Their work ethic didn't stick long-term.

When he was in matches, Buehning preferred to win quickly or not at all. Once he defeated Guillermo Vilas in straight sets, arguably the best win in his career, with a deliberate strategy of not allowing any rally to go longer than three shots. He just blasted for the lines and that day it came off. The Volcano could be very, very Kyrgios.

Buehning eventually toned it down to some degree, explaining: "Fines have gone up. Now I don't take it out on the linesman as much. I try to keep the volume down." But it wasn't a sudden access of maturity that weakened The Volcano's mighty serve. It was bone spurs in his feet. He had operations to remove them, but he returned to the court too soon and the debilitating foot injuries came back.

At 25, having been ranked in the world top 10 in doubles and threatening to break into the top 10 in singles, he was forced to retire from the professional circuit because, he said: "If you can't run, you can't play tennis, so that was it!"

And so The Volcano became extinct.

How does that relate to Kyrgios? Well, a career is fleeting. You can be a player of unlimited promise one minute, eventually settle down and find inner peace and reach your potential ... or it can all blow up in your face and your moment of unlimited promise turned out to be your career.

That's one thing, but the interesting thing is what happened later. In a short online profile of Buehning called 'The Natural', tennis writer Nancy Gill McShea quoted the Bernard Malamud novel (and Robert Redford movie) of that name, about a baseballer who never achieves his potential: "We have two lives, the life we learn with and the life we live with after that..."

The Volcano, done with tennis at 25, had finished the live he learned with. Then he started living the life after that. He joined the family plastics concern, and then, after it was sold, another plastics company, as its international sales director. You can look him up on LinkedIn. The Volcano was sales director for the Accurate Products Company for 16 years, from 1987 when he quit pro tennis until 2003, when he was in his forties.

He got married and had three children who all went to college and excelled at lacrosse, soccer and tennis. After moonlighting for a few years as a tennis coach while still in the plastics business, he joined the John McEnroe Tennis Academy, where he has coached for the past nine years. In 2017 he was reported as getting into arguments with coaches and parents of opponents.

After all that? You had to love The Volcano. He said what he thought and was brave enough to say what a lot of others would only whisper.

Just like Kyrgios saying what so many others think about Novak Djokovic, Fritz Buehning dared to say aloud that Brad Gilbert was the most unpopular player on tour and "everyone hates him". He didn't always make friends, but he spoke for something at the complicated, isolated heart of professional sports, and he was a memorable personality for the way he expressed it.

But really, it's about the life he lived with after that. My hope for Nick Kyrgios is not that he finally wins a grand slam and meets all those volcanic mountains of expectation that are heaped upon him and, wind up the cliché machine, finds 'redemption'. My hope is that he gets to work for a plastics company and becomes its international sales manager for 16 years. My hope is that he finds happiness in a relationship and gets to have three kids to love. My hope is that in 30 years' time, he's some fat guy sitting on the side of some tennis court having a go at the other parents. And that the past won't seem so serious, and that other people will say that they remember him, he was a tennis pro who struggled with the emotional pressure, and for some of them he was an atrocity but for others, for reasons they could never quite put their finger on, he was one of their favourites.