LockerRoom:A few weeks ago on this patch of grass we criticised Tiger Woods for settling for being a knacky golfer and über corporate shill when he could have been so much more.

There was, it has to be said, an overwhelming avalanche of indifference to this contention, but what few dissenting emails or letters dribbled in all made a couple of odd points: firstly, that it was great tribute to the world that a man of Tiger Woods's racial background had made it so far and, secondly, that Tiger Woods lends his name to lots of charity stuff.

The first point seems hardly worth picking up even with a pair of tongs, and as for the second, well is nobody else nauseous from the cloying stench of bought sanctity and PR gimmickry which comes off the entire celebrity-charity industry?

The old Jack London line comes to mind about how throwing a bone to a dog is not charity. Sharing the bone with the dog when you are hungry is charity.

Tiger might stand still in his bespoke Nikes some time over the next few days to reflect it was 40 years ago this week that Muhammad Ali was asked to report for induction to the US army in Houston, Texas. April 28th, 1967, to be precise. A hugely significant day in modern American history.

Ali rests today as maybe the most beloved sports hero in history, the poignance of his condition granting him a still serenity and allowing him to squeeze out that sweet line, "I spoke plenty." He has his place in our hearts and in our imaginations only because we knew there were no back doors. When unpopularity and sheer hatred came his way he stood up and took it all like a lightning conductor. This, after all, is a man who on the day after his first stunning defeat of Sonny Liston held a press conference to announce his involvement with the Nation of Islam. He told the assembled hacks, most of whom hated the new champ with a passion, "I don't have to be what you want me to be."

He declined, unlike Tiger Woods, to stand beholden to the white audience, the white TV executives and the white endorsement-deal sharks. You can imagine that defiant phrase being used today but only when rethreaded by a roomful of marketing gurus looking for something to appeal to that tricky 13-to-25 demographic.

Ali aligned himself with Elijah Muhammad and Malcolm X, the two most hated black faces in the USA. He placed himself at the most radical end of a spectrum despised by mainstream America.

Identifying not with the integrationist civil rights movement but standing shoulder to shoulder with those who said America was irredeemable, he ran the very real risk of stopping a bullet, as Malcolm X or James Meredith or Martin Luther King did.

He drew upon his head the wrath of a nation. Endorsement deals were scrapped, TV appearances cancelled. The WBA began looking for ways to strip him of his title. But he kept true to himself and his instincts.

We think often of Ali's insane yanking of Sonny Liston's tail on the two occasions they fought, or the mad, mad bravery of the rope-a-dope tactic which felled George Foreman, who had succeeded Liston as the scariest man on the planet. We forget the bravery of the life he lived and the choices he made.

Ali enmeshed himself in the world he lived in. As Mike Marqusee in Redemption Song points out, Ali's "career was shaped by his intimate interaction with political and social change." Have any top sportspersons since then immersed themselves quite so deeply in the times they lived in?

Ali was hated by the curmudgeonly sportswriters of America before he first whupped Liston. He took his title and his loud mouth, however, and parlayed them into the more widespread hatred he drew upon himself at the most combustible time in modern American history.

In 1966 he appealed his original draft call-up when he was reclassified as fit for combat. Strafed by questions at a press conference after a training session in Miami, he blurted out one of the defining statements of the era: "Man, I ain't got no quarrel with them Viet Cong."

Those words are a little threadbare by now and time has stripped them of their context and given them a jokey flippancy. The reaction back then was instant and overwhelmingly hostile, making Ali a pariah. In a nation at war, a nation which in such circumstances likes to march to the beat of one drum, for a young black sportsman to demur like that was profound. He had aligned himself with another world.

More than that. Ali prefigured Stokely Carmichael's black-power template by a couple of years, emerging as a new kind of black hero. He infused the anti-war movement with a necessary and reviving confidence, and in his refusal to be what mainstream America wanted him to be he became a global embodiment of a new type of consciousness.

Almost a year after the "no quarrel" statement of April 28th, 1967, one of the central dramas of the 1960s came to its climax in the Federal Customs House in Houston, Texas, not the place one would have thought a reviled black sportsman would choose to face down Uncle Sam.

Ali filled out forms for half a morning and then when the induction ceremony took place in early afternoon a sergeant at arms called Cassius Marcellus Clay by name. Ali refused to cross a yellow line marked on the floor. The scene played itself out three times and each time Ali refused.

He was advised he was committing a felony and was henceforth liable to a prison sentence of five years. An hour later the New York State Athletic Commission suspended his licence and stripped him of his title. Every other boxing body followed suit, even in Britain and Europe.

At the peak of his powers Ali began a three-and-a-half-year exile from his sport. He was sentenced to five years imprisonment and given a $10,000 fine. He never went to jail.

Four decades on, the world of sport has become so expedient to the world of money it is impossible to imagine any great sports star taking any stand on any principle.

As the great and grumpy basketball player Bill Russell noted of Ali, he was the first truly free man in America. He rose to the top of his profession and for the sake of a principle he felt in his gut he threw it all away.

We forget sometimes how audaciously radical and brave it was of Ali not just to be outspoken and loud and playfully boastful but to turn the old masculine world on its head with proclamations of his own prettiness and beauty.

Forty years ago and as a catalyst for change Ali's contribution remains unmatched generally and certainly not even challenged among sports stars.

What made him beloved in the end was his capacity for generosity, his ability to absorb so much hate and come back with a smile on his beautiful face and a one-liner on his lips and never complain about his fate. What appeals when we examine those years is the sense of aloneness you get from Ali, the sense of a man not being handled or packaged or manufactured but just delivering himself unto the world.

Tiger and others have dispensed with generosity in order to practise ostentatious charity. We never expected there would be another Ali but we hoped perhaps that if a black man was ever the greatest golfer in the world he would carry the torch for a while. Tiger is, however, as Ali put it in his own time when speaking of Sammy Davis jnr and others, "too busy cocktailing with whites".

Ali talked the talk better than anyone. He walked the walk with more courage too. Forty years on, white men in suits have found a more subtle way of stifling successors.