There are always caveats attached to the first round of any new AFL season, usually along the lines of its capacity to throw up rogue results which end up being more the exception than the norm.

There’s a few teams after the opening round of 2018 who will certainly be hoping that’s the case. None more so than the Western Bulldogs, belted by Greater Western Sydney and, in the process, losing a critical part of the midfield equation in Tom Liberatore for the season.

Or Fremantle, never in the hunt against Port Adelaide and beaten by 50 points. Or Collingwood, for that matter, who, not for the first time in recent history got the effort part right against Hawthorn but fell down badly when it came to execution.

But is the “round one rule” necessarily right? Recent seasons tend to suggest not.

Last year, for example, eight of nine round one winners ended up finishing higher on the ladder than the teams they beat. And the only exception, Brisbane, which beat Gold Coast by a kick, finished less than three per cent behind the Suns at the foot of the ladder.

It was six out of nine in 2016. And eight of nine again in 2015. That’s 22 out of 27 winners over three years whose round one victories actually did provide an accurate barometer of their prospects relative to the teams they defeated.

And this season? Well, while there were certainly some good games and plenty of individual highlights, neither was there really anything approximating a boilover. Indeed, if five months from now all the round one winners finish higher on the ladder than the losers, it’s fair to say no-one will be overly surprised.

Certainly not GWS finishing some distance ahead of the Bulldogs if Sunday’s obliteration in Canberra is anything to go by.

Toby Greene laid waste to the dismal Dogs with four goals. Photo: Getty

It’s only 18 months since that epic preliminary final between the same two teams catapulted the Dogs into their first grand final for 45 years. There’s an unmistakeable trend since then. An equally narrow victory to the Giants a bit under a year ago. An eight-goal margin last August. And nearly double that this time.

GWS looked sharp, hungry and potent, Jeremy Cameron, Jonathon Patton and Toby Greene bagging a dozen goals between them. The Dogs were listless, then lifeless, outscored 13 goals to just two in the second and third quarters.

Liberatore’s loss for the season for a second time in four years is a bitter blow to a side which already needed all hands on neck after serious injuries to defensive pair Dale Morris and Marcus Adams. The Bulldogs were already banged up. Now, so is their confidence.

Not that they’re on their own on that score. And perhaps for a couple of other teams, more disturbing even than the Dogs’ shocker was their own reversions to recent type.

Fremantle went to Adelaide Oval and got smashed by Port. Not much different there, the Dockers having now lost their last five appearances at that venue by an average 68 points.

Port Adelaide’s new recruits proved instrumental in its round one victory. Photo: Getty

This time, they managed just nine goals. Damningly, that’s in fact more than in any of those previous four defeats. Freo’s best players were Nat Fyfe, Lachie Neale and the 35-year-old Aaron Sandilands. Not much encouragement for the future in that list.

Which is probably what the Collingwood army were thinking on Saturday night as again they watched their team expend plenty of effort and energy for not nearly enough reward.

The Magpies are serial butcherers of the ball these days. Hardly for the first time, they won the clearance and tackle counts, broke even for contested possession and inside 50s, yet kicked just nine goals and ended up losing by 34 points.

They still lack class beyond the big names patrolling the centre square, have an American in Mason Cox still learning the game and a converted defender in Ben Reid as their key forward targets, and have swung a one-time forward in Darcy Moore into defence.

That didn’t strike you pre-season as a mix which was suddenly going to turn Collingwood’s fortunes, and the sceptics (and there’s a lot of them) are going to need even more convincing now.

Not that every loser had a tale of disaster to tell. Melbourne should have ended up taking the points against Geelong.

Ruckman Max Gawn’s last-minute behind saw Melbourne fall 3 points adrift against Geelong. Photo: Getty

Max Gawn’s misfire with 20-odd seconds left on the clock and from only 25-odd metres out cost them the win. But the Demons did claw their way back from a near five-goal deficit against a pretty decent team to give themselves a chance.

Carlton’s effort against Richmond to open this new season was also noteworthy. Yes, the Blues went under. But unlike much of the past couple of seasons as coach Brendon Bolton has drilled the defensive essentials into his young list, this time at least Carlton fired a few shots rather than just limit the damage.

Charlie Curnow and Matthew Wright booted five goals each and the Blues managed 15 for only the sixth time in Bolton’s 45 games in charge. That’s at least something to build on.

And the best thing about round one is that there’s another 21 chances to do just that. As coaches often stress, the first game certainly isn’t the be all and end all. Neither, though, for a few clubs in particular this week, can it be seen as some anomaly to be casually dismissed.