Tomorrow’s election in the Northern Territory got a small flurry of media coverage in the rest of the country this week, not for anything that the participants did but for the fact that a punter bet $100,000 with Centrebet on Labor to win, at odds of 10-1 on.

I never recommend gambling, but to me that looks like a certain gain of $10,000. Centrebet in response has shortened its odds (Labor’s now about 1-14, with the Country Liberals at 7-1), but over at Sportingbet you could still get 1-10 this morning. There’s not many other places where you can make 10% on your money in a week.

On a racecourse, betting like that would be risky in the extreme. But an election is not chancy in the same way as a horse race: horses occasionally come home at 100-1, but candidates don’t.

So why is Labor such a certainty for tomorrow? Antony Green’s invaluable pendulum shows the situation. The CLP had only four seats in the last parliament (against Labor’s 19 plus two independents), but a redistribution has narrowly given them another two notional seats, plus one from a retiring independent. A further two Labor seats have margins of less than 2%.

That means just a small uniform swing to the opposition would give them nine seats to Labor’s 15. But the next most marginal Labor seat, Sanderson, has a margin of 10%, and to get to twelve seats and possible government (if the independent supports them), they would need a completely unbelievable 15.7%.

Swings are never uniform, and with the Territory’s miniature electorates they can be especially erratic. But it’s still true that deviations will roughly cancel out. A small swing to the opposition, which is the most anyone expects, will yield a small gain in seats, even if they are not the ones the pendulum indicates.

For example, Sportingbet’s odds on individual seats have the CLP winning only one of the two Labor marginals (Port Darwin), and losing Drysdale, one of their own

(notional) seats, but picking up two safer Labor seats: Fannie Bay and Fong Lim. Swings and roundabouts, for a net CLP gain of just two seats.

For what it’s worth, I think even that might be overstating the opposition’s prospects. I can’t see a single Labor seat that they should be confident of winning, while three of their own are in some danger.

They’re still more likely to go forwards rather than backwards, but don’t be surprised if it’s only by one seat.

Exotic as the Northern Territory is, its behavior in the last few elections has been very much in line with states at the same point of the cycle. Second-term state Labor governments have so far been invulnerable, losing little if any support — think NSW 2003, Queensland 2004, Tasmania and Victoria 2006 – so the likelihood is that the Territory will go the same way.