Bob Carr’s retirement has many observers talking up the chances of a Coalition victory at the next NSW election, due in March 2007. Such a victory is not impossible, but it’s worth pointing out how unlikely it would be.

Labor has an absolute majority of 17 in NSW, or 19 with the help of left-wing independent Clover Moore. So to win government, even with the support of the other five independents, the Coalition would need to win ten seats. Under the new electoral boundaries, according to Antony Green’s calculation here, that would require a uniform swing of 8.9%.

Swings that big do sometimes happen. But in all of Australia, as far as I can tell, no party has won an election from that far behind since World War II. The comparison is being made with Nick Greiner’s victory in 1988 following Neville Wran’s retirement, but his task was much more modest – the swing required seems to have been a little under 6%.

One would think, therefore, that John Brogden’s opposition would still be a pretty long shot. But that’s not what Centrebet says. It has the Coalition hot favourites at 7/4 on, with Labor at 5/4 against. Labor’s odds are shortening – last night, when I put some of my own money on, you could get 6-4 – but for anyone with a gambling bent those are remarkably good odds.