At last week's US Open we saw Novak Djokovic fall short of becoming the first man to achieve a calendar-year Grand Slam in 52 years.
He would have passed his great contemporaries Roger Federer and Rafael Nadal for most career Grand Slam titles - the three presently remain tied with 20.
Of the trio, Djokovic is cast almost as a villain. In professional wrestling parlance, he's the 'heel' to a couple of 'baby faces'. He'll never be as beloved as Federer or Nadal.
That fact is discussed and analysed more than his prodigious achievements. Regardless, he's almost certain to finish ahead of them in title victories.
Much like Cameron Smith in our game, he looks set to simply render the GOAT debate moot with sheer force of numbers.
What all tennis fans do universally acknowledge is how fortunate we are to witness the emergence of the three greatest players of all-time - in the same era. Few sports are ever so blessed.
As this year's NRL finals roll around, it's worth considering whether we have recently seen that era in rugby league come and go without really noticing.
For the best part of two decades there's been a consensus 'Immortal in waiting' running around. From Andrew Johns in the early 2000s passing the torch to Darren Lockyer then on to Jonathan Thurston.
Throw in Billy Slater who, at least statistically, is the best fullback the game has seen. Those blessed enough to have watched him know he lends far more than mere numbers to that argument.
All the while, like Djokovic, Smith just quietly rolled along collecting trophies and records to ultimately finish ahead of everyone. They were million-dollar players before million-dollar players were a thing.
Not since the Dragons' 11-premierships era has one elite class of talent run around at the same time.
Great players yes, Immortals no. Opinions will differ on that but, given the way the concept was streamlined at the last induction, if they're not one by now, they're not going to be.
Lockyer will be next, then so on and so forth.
It brings us to the present day and the finals series. It has set a stage for the next true champion who wants to step up and take it by the scruff of the neck.
A look back over the past decade and it was really only Cronulla in 2016 that claimed the title without a genuine superstar.
Smith piloted Melbourne to the title last year, and conquered the mountain emphatically with Slater and Cooper Cronk in 2017. The big three did the same in 2012.
Cronk was there for the Roosters in their back-to-back titles. Thurston booted the match-winning field goal for the Cowboys in 2015. Greg Inglis got the Rabbitohs home in 2014.
Inglis and Cronk will probably fall just short of Immortal status - the latter will likely boast the best overall resume of anyone not to earn the honour.
What makes this finals series so intriguing is that there is not a Smith, Thurston, Slater or Cronk in sight. The throne is vacant.
Tom Trbojevic is hurtling towards a Dally M Medal with a vein of form most of us have never seen, but can he get the Sea Eagles over the line?
Like the Sydney CBD proffers for the Northern Beaches faithful, it looks very much a bridge too far, for this season at least.
He asserted this week that he's not even the number one No. 1 - saying James Tedesco still holds that mantle. Teddy has made his own case for an injury-ravaged side this year.
It's even more interesting as far as playmakers go. Cronk retired in 2019 as the game's reigning great half. He's yet to pass the baton to a worthy successor. Who will it be?
At 23, Nathan Cleary's ceiling is the highest of any new-age player. Still, talk of big-game yips linger and will only grow louder if the Panthers go out with a whimper this year.
He and his team were flat-out 'out-finaled' by Souths last week, with Adam Reynolds shaping as both a trump card and major embarrassment for the Rabbitohs given they're moving him on next season.
Cronk pointed out earlier this year that, as playmaker-in-chief, Reynolds has fallen at the preliminary final stage on three consecutive occasions. He won't get a better chance at clearing that hump than the one he has now.
Cameron Munster has picked up the 'big-game' player tag in recent years but he also has a history of big-game brain fades.
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Mitch Moses will need much more than a strong performance against the Knights - side that finished 12-12 for the season - to shrug off his flat-track bully reputation.
They're demonstrably marvellous players, but the prospects of Daly Cherry-Evans and Keiran Foran rest on Trbojevic. Those of Drew Hutchison, Sam Walker and Lachlan Lam are tied to Tedesco.
With the possible exception of a future Cleary, none are in the class of a Johns, Lockyer, Thurston, Slater, Cronk or Smith.
It's not a knock on the present mob to fall short of such demonstrated greatness. It says more about how blessed we have been as fans to witness the era just gone; just as tennis fans have savoured the three kings era.
To borrow a boxing analogy, rugby league has not yet crowned a new lineal champion. With Smith's retirement, we're in the midst of a transitional era waiting for a player to really take the competition and make it his.
We simply don't know who that guy is yet, or who it will be in two or three years' time, possibly longer. He may just emerge in the coming weeks.