Severiano Ballesteros changed the world. Or, at least, he changed some aspects of the way we see it. Now that he has fallen so frighteningly ill, it is good to reflect on the impact he made. People in sport really can change the way we see sport and the world. Here we have them, then: ten athletes who changed our understanding.

1. Severiano Ballesteros
You can take golf out of suburbia; Ballesteros did all that was humanly possible to take suburbia out of golf. When Ballesteros emerged, golfers were British or American, and, to a man, dull. Ballesteros came in with fire and passion, with drama and risk, and if any person can make me look at golf, he has done something exceptional.

Ballesteros played a game freed from the usual restraints and golfers saw new and thrilling possibilities in him. But golf also involves a seriousness, lack of frivolity, and it implies close links with money and power in Great Britain and the United States. Ballesteros brought southern Europe and Latin intensity into this axis. He made the world a less stodgy place.

2. David Beckham
The former England captain's achievement is the global trivialisation of a local triviality. His triumph, his legacy is not of substance but of image. He brought sport into the global culture of celebrity so that in the end Beckham has become more famous for being famous than he ever was for playing football.

But he has done so without conforming to a stock image. In many ways he is the antithesis of the traditional footballer: a family man, uxorious to the extent of accepting a public pussy-whipping, and he prides himself on the sexual ambiguity of his image. Beckham, a man good at free kicks, is now a money-spinning fame machine that reaches across the world, even beyond football's last frontier, the United States.

3. Ayrton Senna
The three-times Formula One world champion had a level of self-belief that touched, perhaps went beyond, fanaticism. Accused of some routine racing misdemeanour, he responded, baffled: “But I am Senna.” His transcendental intensity made him one of the most enthralling figures sport has produced. He was a man utterly committed to what he saw as his destiny of greatness.

It is not his life but his death, though, that brings him to this list. Senna showed that however exalted your view of yourself and your life, there is but one end. And if that doesn't change the way we understand the world, it certainly confirms it in the most shocking way.

4. Olga Korbut
The Cold War was carried into the Olympic Games of 1972, as always, by the grim Soviet sports machine. In the gymnastics hall, the statuesque diva Ludmilla Turischeva competed with unsmiling grace and unwavering hostility.

Then came Olga. In the ultimate piece of upstaging, she reinvented her sport before the eyes of the world, turning it into a pursuit for daredevil pixies. She took terrifying, unheard-of risks and loved the camera with an intense passion, bringing her incandescent charm to the entire world. There were gorgeous, delightful human beings behind the Iron Curtain and the world could not believe its eyes.

5. George Best
In the 1960s, we discovered the working classes; why, they were witty, they were sexy, they were brilliant and every middle-class person wanted to be like them, though without the poverty. The Beatles and George Best changed the way that English people view social class, and that is one of the greatest miracles that ever took place.

Best's brilliance and rebellious style changed football from the niche pursuit of working-class men to a national passion. He split opinions, because the Sixties was a time of polarities, but he stood for freedom, for escape, for a new vision of freedom and classlessness.

6. Kapil Dev
Cricket is an Indian game accidentally discovered by the English. The opening line of Ashis Nandy's The Tao of Cricket came true in 1983, when Kapil led India to victory in the World Cup. Neither Indian cricket, nor world cricket nor India itself would ever be the same.

Previous Indian cricket heroes had been languid, wristy batsmen or clever, vulnerable spinners. Kapil was a hard-whacking, fast-bowling all-rounder with a warrior spirit and, because of him, India is now the country that matters in cricket and, at least partly because of him, India is a leading power in the world, a place rocking with nationalism and self-confidence.

7. John Curry
The world and Olympic figure-skating champion in 1976 combined athleticism with a dismaying elegance and grace. Though the sport has moved on technically, Curry's routines are still extraordinary. He was one of the few skaters who used his arms not as rigid balancing poles but as fluid, moving limbs in a fully realised dance.

He was outed as gay in the year of his triumph and no one was terribly surprised. More relevantly, no one seemed to mind very much, either. It seemed that it was perfectly all right for a gay man to represent his country and to do so with a sexually ambiguous grace. Curry was a competitive sportsman, not a public entertainer, and his victory played an important part of the change in the way we view sexuality. A gold medal always helps us to see the world in a different way.

8. Muhammad Ali
It was difficult enough to cope with the idea that a black man should be clever. But that a black man should not only be pretty but boast of his prettiness - well, that was deeply and truly shocking. Deeply beloved now, Ali was supremely hated by millions before the tide turned.

No such list as I am compiling is complete without Ali. Barack Obama would not be fighting for the US presidency were it not for Ali and perhaps I wouldn't be writing this and you wouldn't be reading this if not for Ali. Ali made sport matter.

9. Billie Jean King
It is not too much to say that King changed the possibilities for 50 per cent of the human race. Certainly she was part of the process of feminism: the change, not just in the role of women in society, but also in the role of men, and in the way the most intimate moments of our life should be lived.

For King, sport was a cause in itself, but it was also an aspect of the cause of feminism. Her famous televised match against Bobby Riggs - the “Battle of the Sexes” - was a milestone, a symbol of the journey so far. It was a match with millions of winners.

10. Roger Bannister
In 1954, Bannister ran the mile in less than four minutes. It was not an athletic milestone, it was a journey to the moon, the squaring of the circle, the invention of a perpetual-motion machine; it was every impossible feat that humans had contemplated.

It didn't come out of the blue; rather, it was a matter of long expectation, but even so, when the moment came it was a revolution in perception. The impossible barrier has yielded. There was surely nothing that humans were not capable of now.

Subsequent years proved this a million times over. There is no limit, it seems, to what humans can create; to what humans can destroy.