For Super League players to be given a chance in the NRL they have to be at the top of their game. The likes of Sam Tomkins, Joe Burgess, Dan Sarginson and Joe Wardle are some of the most recent players to have tried their hand in Australia's elite competition. However, all four came back to Britain with their tail between their legs after failing to hit the form that had earned them an NRL contract in the first place. It is no surprise either that three out of these four - although Wardle actually began his career as a centre - are backs.

In contrast, those that have settled in Australia and played out a great deal of their career in the NRL - such as Sam, George and Tom Burgess, Gareth Ellis, Adrian Morley, Elliott Whitehead and Josh Hodgson - tend to find their home in the forward pack.

But, why is it that forwards take to the Australian game so much easier than backs?

Style of play

Super League is renowned for its more open, expansive style of play as opposed to the more structured Aussie game. This plays into the hands of three-quarters who are often given the ball when the middle men and half-backs chance their arm. Throwing the ball around is a key facet of the British game with long range, spectacular tries becoming more and more common. For example, Wakefield hosted local rivals Castleford on Thursday night in absolutely abysmal conditions, yet, the horrendous weather did not stop Trinity from scoring an incredible try. A pinpoint Liam Finn kick was chased down brilliantly by winger Ben Jones-Bishop - the latter whom ridiculed one of the Sky pundit's opinion that this was not "a game for wingers".

The decision by Finn to kick was not just a risk given that the ball could easily have slid over the dead ball line, but it was also early in the tackle count. In Australia - where the focus lies on keeping to structures and building pressure - such a move would very rarely be tried. This, along with the fact that NRL sides - even in perfect rugby conditions - seldom slip out of the uniform tactics applied by their head coaches, stifles the back line.

On Friday, South Sydney only looked their thrilling best towards the back end of their game against Canterbury when they threw the ball about in an attempt to claw back the 10-16 deficit. Two tries in the final seven minutes gave the Rabbitohs the win, but it was only when they let loose the shackles that they were able to snatch victory.

For 70 minutes of that fixture, the Rabbitohs' back line saw little of the ball. It is no surprise therefore that three-quarters that have gone Down Under such as Tomkins, Burgess and Sarginson appeared quiet in games and that when they did get the ball they were closed down almost immediately.

A forward game

Because NRL sides are so determined to, effectively, grind the opposition down via their forward packs, there is just not that space that the likes of Tomkins had previously exploited in Super League. In turn, this style of play also allows forwards to get more involved and hog the limelight in a way that the less forward-orientated Super League does.

The NRL is also mainly defence-focused with more emphasis on slowing the ruck down.

Whilst there is an ever-increasing importance placed on the so-called "wrestle" in Super League - the act of trying to place an opponent on his back in the tackle to slow the play the ball down - a lot of NRL teams actually employ wrestling coaches. It is an area that they have tried to pinpoint as a way to dominate the game.

Forwards such as James Graham and Sam Burgess - whom were impressive in Super League - have been able to take their games to the next level because of the importance they have as middle players to win the ruck. And, of course, as two referees officiate a game in the NRL, the fixtures are more closely policed, increasing the significance of winning that forward battle to an even greater extent.

Gap between the top and the bottom

There is also a key difference between the NRL and Super League - the gap between the best teams and the bottom teams is much wider in Britain than Down Under. In the NRL, every team is hard to beat and they are very close to each other, whereas here there's that gap between the top half and the bottom half. Despite the fact that bottom-placed NRL side Newcastle Knights played a game extra than tenth-placed Catalans Dragons in 2017, they had the same points difference at the end of the regular season with minus 220. The same disparity was also true at the top; Castleford Tigers finished the regular season with an astonishing plus 391 points average, Melbourne Storm plus 297, despite Storm playing an extra game than the Tigers.

Though blowout scores are not uncommon in the NRL - indeed, St George thrashed the Gold Coast Titans 8-54 a week ago - they are seen much more in Super League. Whilst the three-quarters in Super League can thrive off this more open, attacking game - particularly those in the top half of the table - the same three-quarters almost have to change the way they play when making the transition in the NRL. Gone are the days of chancing your arm in your own half, instead, the forwards take over, enabling the likes of Graham, Burgess, Whitehead and Hodgson to dominate games.

The argument that those three-quarters that have gone Down Under are just simply not as good as those forwards that have is relevant - Tomkins and Burgess were not in the same league as Ellis and Graham when they moved to Australia.

But, they were brilliant in their own back-line positions and starred in the top flight. Even then though, such players were made to look distinctly average in a league where they were not allowed to express themselves as easily in Super League. The way the NRL is played falls into the hands of forwards and it is very difficult for the backs to overcome this.