Deaths in sport carry more power to shock than deaths elsewhere. We turn to sport to get away from the cares of everyday life. In most newspapers you have death, war, destruction and horror at the front, and then, at the back, as far away as possible, you have all the joys and frivolities of sport.

Death has no place here. That's why, when it happens, it's so peculiarly devastating. The death of the Australian batsman Phillip Hughes makes that desperately clear. What mattered about Hughes were his cover drive and his back-foot defence and his chances of a completely secure place in the Australian Test team. Not his mortality.

Sport is supposed to be fun: fun for those who watch it and follow it, fun for those who take part in it. Deaths in war, deaths in endeavours to rescue people from drowning: such things are comparatively easy to come to terms with. But death in pursuit of fun has a particular kind of horror.

And yet, sport is often dangerous. Sport may not matter for itself, but when you can get hurt, you have to take it seriously. All sports worthy of the name require intense physical commitment, and many of the best have more than a whiff of danger.

That's because, more than anything else, sport is about courage. Sport is perhaps best understood as a courage-opp: an opportunity for an athlete to find and demonstrate courage, and an opportunity for spectators to recognise and understand courage. Often enough, that courage is of the physical kind.

We make heroes of batsmen who play fast bowling well. When England had losing series against West Indies and Australia in the 1970s, we made a hero of David Steele, who at least stood up to the quickest bowlers on the planet. Long before India became the major power in world cricket, India (and the world) relished Sunil Gavaskar: the best and most courageous batsman against extreme pace.

Everyone who has ever played cricket knows that the ball is hard for a reason: because a hard ball hurts. That makes every innings ever played a small act of courage. Even with all the protective gear that cricketers wear now, they collect lumps and bruises. They're expected to laugh them off and get in line for the next ball.

No fast bowler has ever bowled fast merely to test the hand-eye coordination of the batsman. He bowls fast in an attempt to expose lack of technique - and also lack of courage. In 1981 when the helmetless Ian Botham hooked Dennis Lillee off his own eyebrows to win one of the great Test series in history, everyone relished the duel, the defiance, the courage.

There's a poignant part in the film Moonstruck when the character played by Cher goes to see the opera La Boheme. At the end, she's devastated. "I knew she was sick. But I didn't know she was gonna die."

"You can't run a sport as if the participants were expendable: you must allow them to face the dangers while doing everything you can to make them as safe as they can be"

Deaths in sport are a little like that. We're prepared to salute courage whenever we see it, but the cost of such a spectacle is that people will occasionally get hurt, sometimes badly. And every now and then, people will die. Perhaps rightly, spectators feel more than a touch of guilt when this happens: as if the death came, in an obscure way, in the attempt to please us.

Eventing is perhaps the most glorious test of courage in sport: doubly glorious because it operates on the axis of trust: trust between horse and rider. Earlier this year, two event riders were killed on the same day at different events. In 1999, five riders were killed in the course of the year.

Every rider knows that the sport is dangerous. I have taken part in it myself - I must stress, at the lowest and least demanding level - and found it as wonderful an experience as the world can offer. It's not supposed to be a mad, irresponsible adrenaline hit, like going over Niagara in a barrel: it's a serious test of skill and courage and trust.

The lesson for the people who run sport is to not take that courage for granted. You can't run a sport as if the participants were expendable: you must allow them to face the dangers while doing everything you can to make them as safe as they can be.

So in football they introduced the card system, making players accountable for dangerous actions. In rugby union they are constantly tinkering with the scrum to reduce its maiming potential. In eventing they are always trying to make the fences as safe in use as they are alarming to behold. And in cricket, there are regulations on the number of bouncers permissible and, of course, protective clothing has made the game unrecognisable from the one played more than 30 years ago.

But accidents still occur, and participants still get hurt. Hughes died because he had the courage to take part in a dangerous game. And that is a word that hurts a little: death in pursuit of a game? It sounds like a desperately pointless way to go.

I learned more about this after reading Rick Broadbent on the TT motorbike races that take place on the Isle of Man every year. The course is long, narrow, twisting and lined with stone walls. Since racing began early in the 20th century there have been 242 deaths in racing and official practice. Annually, there are doubts as to whether the racing can go on. And yet it does.

Broadbent wrote of the death of a rider, and the courage of his widow who attended the racing the following year, doing so with nothing but approval for the racing and the impulse that makes people do it. And he made the whole business clear in a single phrase.

So I will use that phrase as my epitaph for Hughes. Like all good batsmen, he was a person of courage and skill. His death was desperately unlucky, and it came in the course of the courageous pursuit of sporting excellence.

A loss. Not a waste.