Forget everything you know about mathematics – the equations, the diagrams, and even all the dirty words you can spell with your state-of-the-art calculator. You won’t need any of that where we’re going.

Instead, we’re venturing to place that is not constrained by commonly held notions of numerical certainty. A place sports stars have alluded to for generations. A place that many thought didn’t exist outside of conversational hyperbole. The fabled land of the extra 10%.

For far too long we fans have rolled our eyes and groaned our collective disapproval whenever a professional athlete suggests he or she is “going to give it 110%”. After all, we all agree that it is impossible to give more than 100%, don’t we?

Well, I’m no longer so sure. I mean, who’s to say that extra 10% does not exist; that, like wormholes which distort the flexible fabric of space and time, the power of the extra 10% is not out there just waiting to be harnessed?

Granted, anything is possible in theory, but I’m speaking on the practical level. Because I’m increasingly certain that I saw this extra 10% manifest itself on Sunday between Perth Glory and Brisbane Roar.

You may recall that, in the weeks leading up to the game, the grand final rematch was publicised as a grudge game – an opportunity for revenge, retribution and, ultimately, revelry for whoever wanted it more.

However, that was really only true for one of the sides.

While Perth and their legion of supporters wanted to make amends for their grand final disappointment, for Brisbane the match held no greater importance than any other opening round fixture from years past.

After all, what did Brisbane really have to prove on Sunday? Win, lose or draw, the club would still hold the A-League champions trophy come Monday morning. And, barring a double-digit defeat, the club was unlikely to lose favour with the pundits as favourites for this year’s title.

As such, it wasn’t all that surprising that Perth were primed for the performance they delivered; nor was it surprising that Roar were ultimately unable to match it.

Simply put, the Glory players had something extra to play for and therefore something extra to give in pursuit of their goal – the fabled extra 10%.

It was evident in the assortment of 50-50 contests, be it in the air, on the ground or off the ball, that Perth’s play had an extra edge that made Roar look somewhat benign by comparison (especially in the final 15 minutes).

That’s not to say Brisbane didn’t give it their all – I mean, these are professional footballers and professionalism means giving it 100% It’s just that all of 100 is still less than all of 110, no matter how fuzzily we render the maths.

Thankfully – for Roar supporters, at least – this weekend Brisbane will be in the right frame to do a number on their opponent.

With Ange Postecoglou’s Melbourne Victory coming to town, Roar become the club with a point to prove and that extra 10% to give.

After all, this match sees the return of the man who publicly said he wouldn’t leave Roar only hours before he did precisely that (on the very day of champions parade, no less). The Brisbane club, from the players and staff right down to the most of occasional of fans, want to square that slight.

Of course, Victory and their supporters won’t be looking at the fixture in quite the same light. Already they face three grudge opponents every season – a local derby against Heart, a traditional rivalry against Adelaide and the big-smoke showdown against Sydney FC.

For Victory, much like Roar last weekend, it will be just another fixture. Important certainly, but no more so than any other in the regular season schedule.

Which is why I expect to see Brisbane return to their usual winning ways this weekend. That extra ten per cent, no matter how it manifests itself on the field, will ultimately be what gets them over the line.

They will want it more, and they will give more in order to get it.

Granted, my sum(mary) won't stand up to any real mathematical scrutiny and I have no statistics to back me up. But numbers can’t explain everything; they merely quantify it.

And, based on the evidence at hand, the numbers suggest an extra ten per cent is equal to three points. It doesn't matter that I can't express it as a function. The only proof I need will be there for all to see Saturday night.