Big Three still the best, but...
By my reckoning, shortly after the US Open finished in September 2018, the Big Three of men's tennis - Djokovic, Federer and Nadal - should have received their birthday message from the Queen for reaching a combined age of 100. Presumably it was divided into three: proportionately according to the number of career tournament victories, with a little extra for Nadal, because the Queen likes his biceps.
It's little wonder, then, that every preview of the Australian Open seems littered with wonderment that, despite the stage of their careers, the Big Three see themselves topping the market for yet another grand slam. It certainly is remarkable: Federer won his first major at Wimbledon in 2003, starting a period of dominance that has seen the trio win an average of three-and-a-quarter grand slams every year since.
Readers should be cautious in how they interpret this situation, though, because whilst it's accurate to say that the Big Three are still the best players in the game, it's wrong to think that they are still dominant in the same way they were at the height of their powers.
Elo Elo Elo
The easiest way to demonstrate this is to look at their Elo ratings - a measure of relative form compared to their fellow professionals - which show that the trio are a diminishing force. Given that they outperformed their long-term average of major wins in 2018 - picking up all four titles between them - this might be difficult to accept.
Nonetheless, according to my Elo ratings, it's the case: each of Djokovic, Federer and Nadal are playing at a level significantly below their career best, with the numbers suggesting that, were each of them to play themselves at their younger peak, they would all be outsiders at upwards of 5.004/1, with their former-better-selves long odds-on favourites.
What these Elo ratings don't consider, of course, is the way that the Big Three have adapted their playing schedules in recent years. All have taken long-term forced rests because of injury or personal issues, and it could be argued that they only seem motivated by the majors these days, seeming less committed to the smaller tournaments, where their dominance has waned. Either way, they are not the consistent Elo-points acquirers that they once were, perhaps explaining some of their recent decline in this sphere.
But not all of it. It's true that comebacks see players losing Elo points as they take time to regain prime form, and it's also true that the experience of the Big Three is hard to beat when they are on form at a major, but what the grand-slam haul in 2018 doesn't show is that, while they may have picked up all four titles between them, they weren't universally omnipresent in each.
Grand Slams were not brilliant for all
Last year, Federer was absent in Paris, and managed only a few rounds at Wimbledon and in the US Open; Nadal only got to the quarter-finals in Melbourne and retired injured in the US Open semi-finals; and Djokovic struggled at the Australian and French. Compare this to earlier in their careers, when it was rare to reach the semi-finals of a grand-slam without all three playing, and it seems that the Elo ratings are telling us something worth listening to.
Indeed, the ratings at the top of the men's game haven't been as compressed as they are now in all the years I've been maintaining them. Ten players are covered by just 200 rating-points, suggesting that, if the best in that list, Djokovic, was to play the tenth-ranked, Medvedev, the Serb would only be the 1.351/3 favourite over his Russian opponent. By comparison, Djokovic, facing a similar opponent in 2016, would have been a 1.051/20 shot. That's the difference between losing one-match-in-three as opposed to one-match-in-20. They may have years of experience to call on, but our trio are more vulnerable than ever.
Djokovic and Nadal two to avoid
So, although the most likely winner - and although helped by the absence of Del Potro - I would not be interested in Djokovic at 2.285/4. He may have been resurgent late last season, but has still suffered some recent big-match losses to Khachanov, Zverev and Agut. And I can't entertain Nadal at 13.0012/1: he hasn't been seen since the US Open, pulling out of Brisbane and Abu Dhabi, and seems to struggle to keep his injuries at bay when on the hard courts. He may well show some form here, which will build to another assault on the French Open, but he is unlikely to reach the final in Melbourne.
Of the three, Federer is the most interesting at 6.6011/2 to repeat his 2018 win. He was imperious at the recent Hopman Cup, beating the likes of Zverev and Tsitsipas without dropping a set, and while not having the same consistency as at his best, his draw looks kind enough, especially if Nadal fails to rendezvous in the semi-final.
I'll be betting on an outsider to wreck the centenary celebrations of the Big Three, though, with Nishikori 36.0035/1, Anderson 30.0029/1, Khachanov 32.0031/1, Thiem 65.0064/1 and Medvedev 90.0089/1 the most likely party crashers. Daniil Medvedev, who got to the final in Brisbane, is the value choice.