The assignment was simple enough: compose a list of things union has borrowed, adopted or even downright stolen from league - but don't mention Sonny Bill Williams.

Not the greatest start, that first sentence, then. Still, given union's predilection for co-opting league's core facets - albeit usually a few decades down the track - there's really no need to bring SBW (oh no, not again) into it at all. The fact is, if you love modern rugby union then you've got league to thank for it.

And if you hate it, you also know where to point the finger.

ONE: Professionalism

Okay, so a lot of the best rugby players got paid regardless of shammatuerism, but technically rugby was a couple of years behind league when it came to seeing the merits of letting hard-working athletes scoff a bit of the financial pie their efforts created.

A couple, of course, being 100 (or 99 years and 364 days, to be precise). In fairness to rugby, it has embraced professionalism rather enthusiastically.

So much so that Tana Umaga could still earn a mountain of French moolah at an age when most men are worrying about their prostate, and even Kees Meuws can still earn a decent living.

TWO: Doing away with rucking

In 1906, league boffins recognised something had to be done about the tackled ball situation.

Standing practice was for every tackle to end in a "scrum", which was really just a loosely controlled fight for the ball. So in came the play-the-ball and, barring an amendment or six down the ages, it was pretty much job done. Union, by contrast, has wrung its hands over the issue for over a century.

Oddly enough, while the end of defenders striking at the ball in 1996 signalled the final evolution of league's play-the-ball, union types of a certain era consider the end of dignified slipper use in modern rugby as the reason the tackle area is still a dog's breakfast.

THREE: Interchange

The genesis of the modern interchange dates back to 1963, when league first allowed injury replacements.

The system was hardly straight-forward, with up to two changes permitted in the first half only. The rule was later tweaked to allow second-half replacements, but only if the player coming on had played at least half of a lower-grade game. By 1981, four tactical substitutions were permitted in league. Union was again quick to catch on the benefits of such a system, introducing substitutions just 15 years later.

Union is yet to officially bring in an interchange system, with teams relying instead on the blood bin and fake injuries to props to rotate players.

Too soon for them , then, one can only assume.

FOUR: Turning scrums into a joke

Actually, they've always been a joke in both codes. But league at least gave up on contested scrums* long ago.

While having recently copied ancient league rules such as holding scrums no closer than 5m from the goal line (1931), not allowing front rows to pack until told to by the ref (1948) making defensive lines stand 5m from scrum (1951), union has bizarrely persisted in making the scrum a central facet of the game.

While that's great news for those who get off watching endless collapses and resets interspersed with large men picking grass out of their studs and moaning at each other, it's doubtful the wider sporting public is fully appreciative of the inherent beauty of a bungled set piece.

* Except for the smart arses at the Sydney Roosters

FIVE: Video ref

As usual league was the first rugby code to jump into the murky waters of television officiating, with the video ref introduced for the 1996 Superleague world nines.

A traditional timeline for union to follow suit would see the concept due to be introduced for the 2086 World Cup.

Remarkably, it only took four years (and a career of Paddy O'Brien) for union to see the value in the system.

Union being union, they gave the idea a posher name (television match official) and let legally blind Australians like George Ayoub do the job.

Actually, the first use of the TMO in international union saw Steve Walsh award a try to Todd Blackadder against Tonga at Albany in 2000.

SIX: The sin bin

Had it not been for the 1981 introduction of the sin bin, world sport might well have been denied the glorious sight of Kevin Tamati and Greg Dowling settling their differences in one of league's all-time great stinks.

Four years after the 10-minute sit down was introduced, Tamati and Dowling showcased its weaknesses (namely that there's not much point in binning players with just 55 seconds remaining in a match, and just maybe they shouldn't depart together).

When it finally came 14 years later, union's adoption of yellow cards also had teething problems.

Mark Cooksley was the first international player to be yellow carded (for punching a Frenchman in Nancy), but it later transpired the rule change hadn't been ratified by the IRB.

As an aside, soccer referee Ken Ashton created the system of yellow and red cards while sitting at traffic lights after attending the 1966 World Cup quarter-final between England and Argentina after an Argentinian couldn't understand referee speak for "take a walk pal".

SEVEN: Meaningful competition

One of the main reasons for the great rugby schism of 1895 was the desire of northern English clubs to play for something more tangible than the joy of putting their heads between rows of other men's buttocks.

In 1892/93 the leading clubs in the north formed leagues.

They ran a longer season, trained players more thoroughly and even introduced special diets such as peas, pie and chips.

That was all too much for the posh knobs of the south, for whom the participation was reward enough. In the space of a couple years league had more cups than Augusta National. The most famous of these, the Challenge Cup, was first played for in 1896.

England's RFU resisted the temptation to put up silverware for 76 years, with a league structure finally introduced in 1972.

The Ranfurly Shield has bounced around New Zealand rugby since 1904 but, let's be honest, teams can go decades without even playing for it.

Meaningful rugby competition began here with the first national championship in 1976.

EIGHT: Sucking at World Cups

The All Blacks may have taken getting blown out of World Cups in horrible fashion to new levels since 1991, but compared to the - albeit World and now Four Nations champion - Kiwis, the union boys are babes in the woods.

The Kiwis didn't even make the final of the first World Cup in 1954 (Great Britain beat France).

In fact, the Kiwis had been knocked out of eight World Cups without reaching a final before the All Blacks started following league's losing example.

The Kiwis and All Blacks might have one title each, but the Kiwis are way out in front in terms of blowouts. The scoreboard of World Cup failures reads: Kiwis 12 All Blacks 5. Suck on that, union.

NINE: France

That's right, France was once a predominantly league territory that was downright stolen by the 15-man game.

For the most part the French wanted no truck with British amateur ideals, instead embracing the professional code wholeheartedly.

Then came the Nazis. Not the RFU. The real Nazis. After the defeat of France in 1940, the French Rugby Union worked with the German-collaborating Vichy regime to re-establish the dominance of their sport.

Union's amateur ethos appealed to the Nazis' view of sport purity. League was banned and all assets of the Rugby League and its clubs were handed over to the union.They were never returned.

TEN: Skill, tactics and (boo hoo) players

Where to start? The banana kick, cross kicks for wingers, rush defence, flat backlines, second-man plays, dummy runners.

League might have been viewed as an inferior sport played by mercenary ruffians, but that never stopped union coaches poaching bits of the game they secretly regarded as rather clever.

Not that union didn't give back, with the traditional payoff an influx of talented by not overly cashed-up players.

These days the talent flow has reversed, with plenty of leaguies - such as, er, Craig Gower (pictured), opting for the big pay checks and easy living union offers.

As one prominent convert said privately on the day he switched: "You get twice the pay and train half as much. It's great."