COMPARISONS are too subjective to be meaningful in a sporting sense – much more instructive and rewarding to celebrate genius in its own right.
The pre-eminent role of Isa Nacewa in the affairs of Leinster since joining in 2008 inevitably invites comparisons with the remarkable talents who have represented Ireland's provinces since the advent of professionalism.
Irish rugby has enjoyed some truly excellent overseas talents over the years. In Leinster, Rocky Elsom and Brad Thorn stand out, while Munster folk would elevate Doug Howlett, John Langford and Trevor Halstead above all others.
Ulster are currently benefiting from the influences of their South African contingent: captain Johann Muller and Ruan Pienaar are their stand-out performers. Connacht have also got in on the act in recent times, with Dan Parks excelling for them.
Nacewa will be missed by Leinster when he retires at the end of the season, and he will be remembered as one of the best to ever grace these shores. In his pomp, he was truly irresistible and he has enriched the European scene with particular flair over the past five years.
For certain, Leinster would have won their three Heineken Cups without him. But would they have done so with such style and flair?
There never was a player without weakness – his kicking from the hand has improved hugely over the years but is still ungainly – but Nacewa's many talents outweigh considerably any perceived shortcomings in his game.
It is his contribution with ball in hand that will be most warmly remembered in years to come. He is as elusive as a vapour, slides through gaps where apparently none exist, fixing opponents to the ground with a deceptive side-step and devastating acceleration.
In years to come, his name will surely feature prominently when a best overseas selection is discussed.
Shaun Payne (Munster)
There was no fanfare when he signed in 2003 from Swansea but his impact with Munster was enormous. Payne is recognised as one of the most accomplished overseas captures of all. He was an integral part of Munster's 2006 Heineken Cup win. He went on to manage the team with less success. As a player, though, he was outstanding, especially under the high ball, and his defence was top notch. Scored 18 tries from 2003-08.
Doug Howlett (Munster)
He has been immense for Munster since joining after the 2007 World Cup. He bows out as their second all-time try-scorer. His legacy in Munster is assured and he is a must on any 'best-ever' list. It is fitting that his final act in a Munster shirt was scoring a try against Glasgow.
Rua Tipoki (Munster)
The former New Zealand Maori was a key figure in Munster's 2008 Heineken Cup success. His reputation is only enhanced when it is remembered that he had to manage a chronic hamstring injury through his two years with Munster. He was also the architect of the Munster haka when they faced the All Blacks in 2009. His time was short but his impact huge.
Trevor Halstead (Munster)
There is a bit of competition, not least from former Connacht player Niva Ta'auso, but for what he achieved with Munster, Halstead deserves to be considered one of the best signings. The South African was always quiet in league matches but in European competition he always showed up for work and scored a try in the 2006 Heineken Cup final.
Isa Nacewa (Leinster)
The problem is where to pick Nacewa ... he is so good in a multitude of positions! With ball in hand, he is a phenomenal player and will be remembered as one of Leinster's best ever signings. He was a huge part of their European domination since 2009 and will certainly be missed.
Felipe Contepomi (Leinster)
There is plenty of competition in the guises of Paul Warwick (Munster), Dan Parks (Connacht) and even David Holwell (Leinster), but when Felipe was good he was truly mesmeric. His temperament made him an easy target at times but for Leinster and Argentina, he was truly outstanding, especially in years when they weren't dominant.
Ruan Pienaar (Ulster)
He had a sluggish enough start to his Ulster career but in the last season and a half, he has become immense. He passes, he kicks, he scores and he directs the Ulster team like a great orchestra conductor. He is one of the world's best in the nine shirt and isn't a bad option at 10 either!
Ollie Le Roux (Leinster)
Hugely powerful, he was magnificent in the loose in particular. Leinster have been well served in this department by the likes of Heinke van der Merwe too, but Le Roux was a standout operator and was adored by team-mates and supporters for his excellence.
Richardt Strauss (Leinster)
He may be Irish qualified but is a South African by birth. He would have provided Rory Best with serious competition in this year's Six Nations but for injury. He is outstanding out of touch and is an excellent scrummager. He is also great in the loose. Leinster did a great bit of business in recruiting him.
Stan Wright (Leinster)
He anchored the Leinster scrum, which is what a tighthead must do. The likes of BJ Botha – especially while with Ulster – and John Afoa are technically better scrummagers, but Wright offered so much more and his impact was all the greater on Leinster's scrum.
Nathan Hines (Leinster)
His offloading game perfectly suited Leinster and he brought an abrasiveness that has been lacking since he left. His work at the breakdown defied belief at times and he's still motoring with Clermont. That he beats off competition from the likes of John Langford (Munster) and Michael Swift (Connacht) emphasises just how good he was with Leinster.
Johann Muller (Ulster)
Muller has proved his worth as a second-row enforcer and Ulster captain in recent times. Whether or not the Springbok invasion is helping or hindering the Irish contenders isn't relevant in this debate. Brad Thorn had a huge influence in his three months in Leinster last season but Muller has been truly outstanding.
Rocky Elsom (Leinster)
He was magnificent in Leinster's first Heineken Cup winning season. There were games in that campaign when he seemed to be a one-man band. He carried, he tackled, he rucked, he inspired. Leinster were truly blessed to get him on the books and he repaid their investment. Hasn't had the best of times since leaving but hopes to revive his fortunes with Toulon.
Ray Ofisa (Connacht)
He signed from North Otago in 2007 and recorded more than 100 caps for the province in a magnificent stint with the Westerners. As a player, he was tireless and tended not to leave a lot behind when he hit opponents in the tackle.
Jim Williams (Munster)
His standing with Munster was so great that he became the first overseas player to captain the southern province. His influence as a player was only bettered by his stint as forwards coach when he helped Munster to the Heineken Cup title.