In rugby union, we know the position in many guises. It's most commonly referred to as inside centre, though Kiwis denote it a second five-eighth. And in Italy the role can be wonderfully referred to as a “primo e centro”.

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Either way, it is one of the pivotal stations on the field. This is becoming even more apparent in this year’s autumn internationals.

Over the professional era, the purpose of the man in the No.12 shirt has varied, according to how each nation wish to play their game.

There are two very basic ideologies that the second receiver in the back line can fulfil. The first is of a supporting playmaker. 

In New Zealand, this is why the position is known as a second five-eighth, operating under the principle that both No.10 and No.12 are dual first receivers who can operate either side of a scrum or ruck.

Often this style of player will also be a capable tactical kicker.

The second is of a power style player. A true inside centre who plays his role very much like a traditional centre, often straightening the attack on offence, or acting as the most powerful blockade off the fringes. 

That is, someone who can tackle a forward coming off the ruck as proficiently as tackling or stopping a backline play.

There is then the third option, someone who is a heady blend of the two above qualities. Great No.12s who spring to mind are men like Ireland’s Mike Gibson or Australia’s Tim Horan - players who are often the beacon for a team in attack or defence.

Tana Umaga is a classic example for New Zealand. In many respects the former All Black captain pioneered the role in aspects of game-changing defence and his ability to act as a roving loose forward.

The Northern Hemisphere is not producing as many quality No.12’s as it would like. Or, more importantly, is not using them effectively or in a manner which complements the entire team’s game.

Jamie Roberts has the potential to be a brilliant midfielder, but the Wales and the Cardiff Blues centre is struggling to define his role.

Wales are not the Lions, and one wonders whether Roberts has adjusted to not having the combined forces of the home unions giving him go-forward ball, and not having the calm advice of a certain 100-Test cap north Dubliner whispering off his shoulder.

Against Australia and Samoa, Wales and Roberts did create opportunities, but were not clinical enough to finish them off. One cannot be too critical as there is no Mike Phillips to create uncertainty in the fringe defence of opposition teams, nor a Lee Byrne scything into the defensive line.

But Roberts at Test level, a player used at 12, 13, 14 and 15 in the backline, has still to learn to use his strong defence and powerful running to create. Certainly being partnered with Tom Shanklin hasn’t helped.

Wales appear to have a mini identity crisis with their midfield. Gavin Henson isn’t there any more and one feels that perhaps a Dan Biggar or James Hook could be better suited to 12, with Roberts feeding off created space.

England are missing this without Riki Flutey, who suddenly appears to be the spark the backline requires.

Ireland do not need to rely so much on this, as they have the magical Brian O’Driscoll. There is far less expectation on the likes of Paddy Wallace or Gordon D’Arcy with quite possibly the most ingenious outside centre ever to play the game alongside them.

In the Southern Hemisphere, the rise of Ma’a Nonu has seen the All Blacks' first-choice midfield elevated to one of the best in the world. However, the dreadlocked centre's role is a lot easier with Dan Carter inside of him.

But it is his combination with Conrad Smith, a complementary but more diverse player than Nonu, who sees the All Black backline perform more efficiently.

While the Wallabies may not exactly be clones of the Crusaders, coach Robbie Deans has certainly pushed the principles of a “second five eighth” into the Australian set-up.

Berrick Barnes has emerged as the anchor the backline operates around - and whilst Quade Cooper may be more flamboyant and less structured than the injured centre, essentially their roles are the same.

The Wallabies play flows more efficiently with their 10 and 12 interchanging.

Most Test nations have depth in their threequarter line or back-up halves, but when a team lose their presence at No.12, they inevitably suffer. 

South Africa have looked less potent without the assuredness of Jean de Villiers in their backline.

Many feel that with a world-class Test fly-half, a team cannot dominate or build towards winning a World Cup.  But as recent matches have shown, lack of creativity and nous at 12 can unhinge even the best side.

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