(Graham Barrett is an English cricket fan in Australia following the Ashes - and rather enjoying what he's seeing.)

It's the most iconic cricketing spectacle of them all. Boxing Day at the MCG.

This year there's added spice. The locals haven't seen a 'live' Ashes game here since 1986. Ever since then the series has been wrapped up in time for Santa's annual, world chimney tour.

This time everything is up for grabs. The series is tied at 1-1. England tantalisingly close to keeping the urn, Australia bouncing after Perth.

Much talk of momentum in the build-up. It's the word on everyone's lips.

Common consensus has it that having momentum on your side is like having another man on your team, and one who can swashbuckle with the best of them. England's glass was full to the brim with momentum after Adelaide. Then Strauss and co turned round after Perth to find that someone had swiped their pint glass. Suddenly the momentum had 'swung' and now Australia has all the forward motion. England cannot even lay claim to any of the remaining dregs left over from Adelaide.

Let's see what the experts are saying:

A common opener in many articles, this one from Yahoo, "The five-match series is currently tied at 1-1, but Australia has the momentum following their 267 run win in the third Test at Perth's WACA Ground."

Justin Langer, writing in his newspaper column: "We have great momentum."

Australian captain Ricky Ponting: "Momentum and confidence is a great thing in sport. We've got the tide going back in our direction now."

Shane Warne: "Australia will win here because they have all the momentum after the win in Perth. In sport, momentum is crucial because it has an impact on everything."

Right. Thanks Shane. That's pretty clear-cut.

He could have said Australia will win because its players are better/ in-form/ used to the local conditions, or any number of other factors usually used by pundits to make sporting predictions. But he didn't. It's solely down to that glorious 'M' word according to the chicken-bite-loving blondie. It must be able to mask the continuing problems Australia is experiencing with its top order (Hussey notably aside)

England are done for. Without momentum there's little point in turning up. Abandon hope all ye Englishmen who enter the MCG.

But hang on. There's another side to this maddening coin. Let's take a look at the English perspective:

Captain Andrew Strauss: "Momentum from Adelaide didn't take us far in Perth."

"A lot's been talked about momentum but momentum only carries you so far. The momentum's changed with every Test."

Kevin Pietersen: "We took momentum into Perth and we got hammered."

So momentum is, paradoxically, crucial to your chances of winning before the match but of little importance if you manage to turn everything on its head and win. Then it's all yours until the next game, where you can continue using its magical powers or discard it like an unwanted Christmas present.

To sum up. If Australia wins at the MCG, well obviously it is clearly the momentum that carried them over the line. If England wins, it can easily be explained by some Anderson-like late swing of the momentum.

Who will have this elusive momentum going into the final test in Sydney?