Not only do they bowl at lightning speed but also they have the attitude to go with it, be it the pre-match taunting of a Glenn McGrath, the intimidating stare of a Curtly Ambrose, the dauntless self-confidence of Fred Trueman or the relentlessness of Dennis Lillee.

They don't spend too much time worrying about a batsman they may have hit. They don't suffer from homesickness. And if they do, they certainly don't admit to it. Unless, that is, they are Stephen Harmison.

Off the field, the Durham quick is an easy-going family man, who can seem indifferent to his own gifts as a bowler, a likeable trait in many ways but one with the potential to rile his teammates.

However, his natural ability to make a ball rise alarmingly off a good length makes the 28-year-old Durham seamer one of the most dangerous bowlers in world cricket today.

It was Harmison who set the tone for England's re-invigorated Ashes challenge last year when, on the first morning of the opening Test at Lord's, his bouncer crashed into Australia captain Ricky Ponting's helmet, forcing the grille into the batsman's cheek and so nicking a cut that needed stitches.

Shortly afterwards Ponting, whom Harmison holds in high regard, was caught in the slips off England's spearhead.

There were many quicks who wouldn't have given the incident a moment's thought. But when England arrived in Australia earlier this month, Harmison's first act was to express his remorse.

"As a bowler and as a person I was disappointed with myself the way it came about," he said. "I didn't realise the extent of the injury until I got back to my (bowling) mark, and by then it was too late. It was probably the one regret of the whole Ashes series."

Harmison is an inconsistent bowler. When he is good, he is very, very good and when he's bad he's anonymous.

Many the time he has brushed aside a mediocre performance by saying his rhythm "didn't feel right", as if there was nothing else he could have done.

But what separates the truly great from the rest is that they achieve an impressive minimum standard below which they seldom, if ever, fall.

Former England captain Nasser Hussain, whose consoling words were widely credited with ensuring Harmison's international career didn't end in embarrassing failure on England's last tour of Australia when the bowler lost his run-up, has high hopes for his old strike bowler.

"On his day Steve Harmison can be the best bowler in the world," Hussain told the December issue of the Wisden Cricketer magazine.

"He has exactly what it takes to be successful in Australia: height, pace and bounce. And the Australians fear him.

"But what I would want from him is consistency.

"The issue for Steve is about not settling for mediocrity: he has got to strive to be the best.

"He has to perform not in one Test in five but in three or four in five. After he took 11 wickets against Pakistan at Old Trafford this (English) summer I would have wanted him to work doubly hard, to make even more sacrifices so that he became not just the best in England, but the best in the world."