We've heard it a bit this week, though. How refreshing it's been to hear the tag applied to a meeting of two teams hardly anyone would have confidently predicted could face-off on the last Saturday in September.

But there they are, the Western Bulldogs and Melbourne, occupying the first two spots on the AFL ladder, and a full two games clear of their nearest rivals in Geelong, Brisbane and Port Adelaide.

And their clash at Marvel Stadium on Friday night really does loom as one of the best games we will see this season.

They've been clearly the most impressive teams of the near half-season completed, striking a groove of consistency for which neither had been renowned in recent times - despite the fact the Bulldogs won a famous premiership only five years ago, and Melbourne reached a preliminary final in 2018.

Their timing might be pretty good, too. Richmond and Geelong are the established heavyweights when it comes to flag contention but the Tigers, at least for now, have their hands full climbing back into the top eight.

As for other serious contenders like Brisbane and Port Adelaide, well, they're not a whole lot more seasoned when it comes to September.

There's certainly a novelty about the look of the top end of the ladder right now, particularly with the quickly-transformed Sydney also lurking in sixth.

The Swans no strangers to September, but this version chock-full of exciting young talent with which we're still coming to grips.

Whoever wins Friday night we can be reasonably confident, given the way both teams play their brand, that it will be entertaining. Perhaps, also, it will help dispel that concept of novelty acts from our minds. Because it's not like either team has come from nowhere.

The Dogs, after all, have been finalists the past two years. And while the Demons' follow-up to their 2018 top-four finish was a disaster, they did improve considerably on that effort last season, finishing only half-a-game away from playing finals.

The reason few pundits were prepared to consider either serious finals players in 2021, however, was the extent of flaws that both have made strenuous efforts to rectify and, so it seems, successfully done so.

Melbourne's midfield group remained prolific in terms of possession post-2018, but the Demons repeatedly butchered the football.

To the extent that in the shocking 2019, they finished fifth for volume of inside 50 entries, but 17th for points scored and dead last for scores and goals per inside 50.

That is a ridiculous contrast, given the weight of opportunity.

Those rankings and numbers improved by degrees last year, but have gone to another level in 2021.

The key is simply in how the Melbourne midfield structures around the stoppages, now with a much better balance and positioning of inside and outside on-ballers.

The Demons have held their ground in the contested ball rankings, but improved markedly for uncontested ball, climbing from a ranking of 15th on differentials in that statistic last year to a current sixth.

Melbourne is winning a higher share of clean, unpressured possession. No surprise, then, that it is converting its opportunities far more efficiently.

The Bulldogs already had an impressive midfield and a defence that was very effective rebounding.

But their deficiencies were highlighted by their record against top eight teams last year, a miserable 1-7.

Over the off-season, the midfield stocks grew deeper still with the acquisition of off-loaded Magpie Adam Treloar, and the less-heralded but important ruck support provided to No.1 man Tim English by former Brisbane veteran Stefan Martin and the emerging Jordon Sweet.

An attack which had never been a strong point (the Bulldogs ranked only 12th for scores in their premiership year) has improved immeasurably.

Aaron Naughton, Josh Bruce and an English now freed to drift forward more a dangerous combination, along with midfielders who double as bona fide goalkickers - no example better than skipper Marcus Bontempelli, who sits third behind Bruce and Naughton on the goalkickers list.

The Dogs are No.1 for scores (the only team averaging more than 100 points per game), creating the most scores from both turnovers and stoppages.

They're efficient, ranked No.1 for scores per inside 50 (49.1 per cent). And all while maintaining their stinginess at the other end, ranked No.1 for fewest points conceded.

They're great to watch, the Bulldogs. As, too, has been their opponent on Friday evening.

This really could be a prelude to a third or even fourth clash between the two teams after their re-match at the MCG in July.

And if gets to that stage, we really will have to acknowledge this ascendancy of both, far from being a cute football novelty, is very much built on solid foundations - and not just another passing fad.