The three other teams in the finals (the first match decides third place and the second is the Grand Final), too, have, clever names chipped from the block of ACT life.

They are the Brindabelters, the Black 'n' Blue Belles (a reference to the ACT's floral emblem) and the Red-Bellied Black Hearts.

For those of us who love roller derby it's because, in Canberra, roller derby matches are, a bit like the ice hockey and rugby league, important parts of the mixture of Canberra life as we know it. As a city we are still a bit prim and bourgeois, and need this rough, working-class entertainment to make us look, smell and sound like a real rough-and-tumble metropolis. Roller derby helps our city's disembourgeoisment.

''They live among us disguised as mums, scientists, students, hairdressers and public servants,'' the CRDL's publicity for this Saturday at the AIS confides.

''But they have undergone a creeping transformation … They have become giants of the flat track! Be prepared for the Attack of the Flat Track Women!''

Lots of the Flat Track Women are artists and one of them, Bettie, proves in conversation to be a very knowledgeable historian of her chosen sport.

On Saturday you'll see, in each match, two competing teams zooming around a track and doing their best to block and bump their opponents. Where this all began, Bettie explains, was during the Great Depression in the US where there was ''this rage for endurance contests''.

We've all heard of the dance contests in which, in search of a bit of prize money, people would dance until they dropped. Well, they roller skated too. ''To make things more exciting for the public the organisers made the skaters have spells when they speeded up and then sometimes they crashed into one another and the people [audiences] loved it,'' Bettie says.

And so colliding and biffing became an essential part of the spectator spectacles.

Its popularity lapsed but there have since been revivals. The 21st century revivals have been especially strong in Texas where roller derby, became, Bettie reports, ''exciting and lots of fun, with punk and rockabilly influences and lots of exotic names''.

And so almost every combatant on Saturday will boast an exotic name (and, though you won't have guessed it, Bullseye Bettie is not the everyday name of the roller derby spokesboadicea we're quoting here who told us she lives ''a rich life of pseudonyms''). On Saturday there will be in action a Bambi Von Smasher and a Sideshow Ali.

Although one of the beauties of roller derby, thrilling for participants and for spectators, is that it allows fit and strong women to play a full-blooded body-contact sport, Bettie says spectators may be a bit bewildered to notice that between very competitive matches, rivals sometimes openly hugging and kissing one another.

Nothing in men's body-contact sports has prepared us for this kind of thing. Men, bless us, are simpletons who don't know to sincerely hug a mate one moment and then determinedly crunch him the next.

Everyone knows everyone else and on Saturday, although they'll all be in their scary-sounding teams on Saturday, deep down everyone is, Bettie says, more committed to the sport than to their team.

Can this even be true? Why not go and see for yourself on Saturday at the AIS at Bruce?

Doors open at 3pm. Game one starts at 4pm, then game two at 6.30pm. Tickets from Ticketek at www.ticketek.com.au