But who wants to watch gentlemen? For as long as the game has been played, the tough nuts have been far more interesting. They come in many shapes and sizes (mostly large). They play in many different positions (mostly in the pack). They are seemingly immune to pain (mostly other people's).
And for all that we tend to think of them all as pretty brutal buggers, there are some subtle differences between them as well. Think of the enforcers Scotland have put out down the years, and you recall the wily ones, like Nathan Hines, the mischievous ones, like Ian McLauchlan, the silent-but-deadly ones, like David Sole, and the good old-fashioned bone-crunchers, like Jason White.
Refreshingly – to some at least – the out-and-out psychopaths are getting rarer and rarer, even in France, their traditional breeding ground. The baleful glare of the television camera has rendered them almost extinct, for nothing gets past its all-seeing eye. And what the referee misses on the day, the citing officer will pick up later.
So who are the hard men of this year's RBS 6 Nations. Who are the guys you would want on your side, but wouldn't want to meet down a darkened alley? When the going gets tough, who are the toughest of the lot?
Age: 26. Position: Hooker. Club: Perpignan. Caps: 42. Height: 6ft 1in. Weight: 17½st
Where to start? Not since the era of Brian Moore has English rugby produced a player as entertainingly irate as Hartley. The Northampton hooker's anger-management strategies make Joey Barton look like Sister Wendy, his years at the top marked by a lengthy – and ever-increasing – catalogue of eye-watering incidents.
In 2007, Hartley seemed to be heading for his first cap, and possibly a place in England's World Cup squad that year, but he was found guilty of gouging and banned for 24 weeks. During his time out, he addressed his on-field behaviour issues through counselling with a sports psychologist, but with little success. Last year, he was cited for allegedly biting Stephen Ferris, the Ireland flanker, and picked up another eight-week ban.
There have also been some high-profile spats with Ross Ford, Richie McCaw and Rory Best. All of which serves to disguise the fact that Hartley is actually a superbly gifted player, technically excellent and without peer at the line-out. If he could keep a lid on his frustrations, he would be one of the greats.
Age: 29. Position: Centre. Club: Toulouse. Caps: 25. Height: 5ft 10in. Weight: 15st.
It is quite an achievement for a 5ft 10in centre to find his way into this rogues gallery. And all the more so in France, the spiritual home of grizzled forwards, simmering enmities and random acts of violence. But Fritz is something special. He has a familiarity with French and European disciplinary procedures that few players can match. And, it seems, an indifference to what anyone thinks of him and his way of going about things. Two years ago, after copping a red card for a dangerous tackle on Wasps winger Tom Varndell, his insouciant response to the derision of the English crowd was to raise a single finger in their direction. For his troubles, he received a hefty fine as well as a lengthy ban.
The Toulouse player was also accused of gouging the eyes of Ireland flanker Stephen Ferris in 2009. He got off that charge, but was still found guilty of punching Ferris and was banned for a couple of games. The French media have exhausted their own language to describe their serial miscreant. These days, they call him "le bad boy".
Age: 25. Position: Flanker. Club: Leinster. Caps: 22. Height: 6ft 2in. Weight: 17st.
The list of genuine Irish nasties is disappointingly short. However, the Emerald Isle has produced a succession of fierce-but-fair forwards who have combined raw strength and fearlessness to devastating effect. O'Brien is only the latest in that line. Some would say he is too big to be a genuine openside. So much for their theories. A powerful country boy, as happy on the family farm as he is on an international pitch, he has immense strength and an apparent disregard for his own safety. When Leinster won the Heineken Cup two seasons ago he was named Player of the Tournament.
A story often told about O'Brien concerns the occasion he was out duck shooting in the company of his dog. It was a freezing day, and when O'Brien shot a duck the dog refused to jump into the ice-cold river to retrieve the thing. O'Brien shrugged, put down the gun, and waded in to collect it himself.
Age: 31. Position: Prop. Club: Leicester. Caps: 91. Height: 6ft 2in. Weight: 19st
It is not so long since rugby's doomsayers were predicting the demise of old-fashioned, teak-tough lumps of malevolence like Castrogiovanni. In the sport's new age, as players got fitter and fitter, they were too big, too slow, too much of a hindrance in the modern game. But Castrogiovanni stood his ground. Literally. An immovable object in the Italy front row, he almost single-handedly ensured this side became a respected, and even feared, scrummaging force in world rugby. Leicester paid a small fortune to bring him to England. Toulon are reportedly ready to pay a large fortune to take him to France.
Castrogiovanni is hard, but fair. At least he is now. Once a promising basketball player, he gave up that game after punching a referee. "I didn't even turn up for the disciplinary hearing," he said. "I knew I wouldn't be playing much more basketball."
Alasdair Strokosch Age: 29. Position: Flanker. Club: Perpignan. Caps: 30. Height: 6ft 3in. Weight: 17st.
A few years ago, Strokosch had ideas of becoming a ball-playing loose forward. He dreamt of popping up in backline moves, delivering subtle passes, maybe scoring the odd try or two. Then Frank Hadden, the former Scotland coach, had a word with him. "Just stick to what you're good at, Al," said Hadden. "Just hit people."
Which is pretty much what Strokosch has been doing ever since. The bullet-headed flanker was a karate black belt before he was a teenager, and he hasn't softened up since. In the business of hitting people, and hitting them hard, he has few equals: a genuine tackle machine.
And the best thing is that he can do it perfectly legally, which is why he has thrived in such notorious rugby roughhouses as Gloucester and Perpignan. He also has a level of courage that few can match, as he demonstrated when he took a gruesome kick to the head in Scotland's match against the All Blacks recently. "Never felt a thing," he smiled.
Age: 25. Position: Flanker. Club: Dragons. Caps: 27. Height: 6ft 4in. Weight: 17½st.
Wales might be famed as a fly-half factory, but the valleys have just as rich a tradition of producing lanky, raw-boned flankers who will tackle anything that moves. The quietly-spoken Lydiate, who models himself on England's Richard Hill, is only the latest in that vein, but is quickly emerging as one of the best.
He has overcome serious adversity along the way. Five years ago, he broke his neck in a Heineken Cup match in France. Flown home in an air ambulance, it was assumed he would never play again, but his courage and strength of character shone through as he rebuilt his life and his game.
He was the second top tackler at the last World Cup. He was named Player of the Tournament in the last Six Nations. "If it was up to me," said Wales assistant coach Shaun Edwards, "he would be man of the match in every game. He is also a joy to coach, and the kind of lad you'd be proud to have as your son."