Every time a federal election rolls around there's a big kerfuffle in political circles about preference deals among parties.
It can give a bit of an insight into who parties would prefer to share the parliament with, or what the faceless men and women of Australian politics have been up to.
So why do the parties care so much? Do they even matter? And what should you know before you vote?
First, a crash course on preferences
For your vote to be counted in the lower house (that is, for the House of Representatives), you have to number every single box.
So you put a 1 next to the person you would most like to win.
You then put a 2 next to your second choice, and a 3 next to your third choice, and so on until you run out of names on the paper.
Preferential voting means that the person who wins the most 'first preference' votes might not win the seat.
If a candidate wins more than 50 per cent of the first preference vote, it's game over. They have won.
This is where the fun starts
But if nobody gets over 50 per cent, then preferences start being tallied.
The second preferences of the candidate who came last are then dished out to the remaining candidates.
That process is repeated with each losing candidate, from the bottom up, until those votes push someone over 50 per cent.
Here's a very simple example
Say there are three candidates in a seat.
If the Liberal candidate receives 45 per cent of the first-preference vote, the Labor candidate gets 40 per cent, and the Greens candidate gets 15 per cent, the vote will go to preferences.
The Greens candidate is knocked out, and all of their second preferences go to Labor.
The Labor candidate would win with 55 per cent of the vote, while the Liberal candidate remains on 45 per cent.
The idea is that 55 per cent of voters would 'prefer' the Labor candidate to the Liberal candidate.
No contest is that simple — but that's pretty much how it works.
So what role to the parties play?
To be crystal clear — only you, the voter, get to decide where your preferences go.
But parties try and influence how you decide which candidates you preference through their how-to-vote cards.
Many parties and candidates will station volunteers near polling booths on election day, handing out instruction cards on how to vote for their candidate.
The cards will often have an image of a ballot paper, with a '1' next to their candidate, and numbers in the rest of the boxes too.
The ABC's election analyst, Antony Green, said they serve two purposes.
The first is to remind you to fill out all the boxes so that your vote counts.
"What they're trying to make sure is that people fill in the ballot paper correctly and number all the squares."
Secondly, they aim to send preferences in the direction that will work best for them politically.
It might mean if they lose, their preferred alternative is more likely to win the seat.
"For the minor parties whose preferences are more important, they might be trying to influence preferences," he said.
"And of course, the major parties talk to minor parties to try and get minor parties to direct preferences to them in the lower house, or do a trading deal with the upper house."
But again, it is just a suggestion.
While some voters clearly follow the suggestion, everyone is free to vote however they choose.
But what are the 'preference deals'?
Political parties, unsurprisingly, love to play politics.
At every election there are suggestions that backroom deals have been cut between major parties and minor parties to send preferences to one another.
For example, at the last election in 2019, the Coalition was reported to have struck a deal with Clive Palmer to swap preferences around the country.
The UAP would suggest its voters preference the Coalition second, and the Coalition would suggest its voters give second preferences to the UAP.
For the Coalition, it would mean UAP votes would flow to its candidates in tight lower-house races where they may be needed to edge ahead of Labor.
And for the UAP, while it was unlikely to win any lower house seats, it bolstered their chances of picking up a seat in the Senate.
As it turns out, the UAP's preferences did not prove decisive to any individual race for the Coalition, and the UAP did not wind up with a Senate seat.
The Coalition did benefit from lots of anti-Labor advertising coming from the UAP, but that's a separate matter.
What preference deals have parties made among themselves?
No deals have been outright confirmed in this election, but there are lots of parties talking about what they will and won't do with preferences.
The Greens have announced they will suggest their voters preference Labor ahead of the Liberals right across the country, and they will support a few pro-climate independents in Liberal-held seats too.
Greens leader Adam Bandt said their priority was changing the government.
"People can safely vote Greens knowing they'll kick Scott Morrison out and their preferences will go to Labor," he said.
"If you follow the Greens' how-to-vote card, your preferences will go to Labor.
"Across the country, Greens how-to-vote cards will recommend preferencing Labor ahead of Scott Morrison and the Coalition."
Labor is largely returning the favour, preferencing the Greens second for the Senate on its how-to-vote cards in every state and territory bar two.
In Tasmania, the Jacqui Lambie Network is put above the Greens, and in the ACT, Wallaby-turned-independent David Pocock has been handed second spot.
Labor also seems to be looking to give some high-profile independents a hand in their races against Liberal MP's, preferencing them second in seats such as Wentworth, Kooyong and Curtin.
Pauline Hanson has said One Nation would use its how-to-vote cards to try and support conservative National Party candidates, and remove more moderate Liberal MPs.
The party will direct preferences away from Liberal MP's like Bridget Archer in Bass (in northern Tasmania), Tim Wilson in Goldstein (in inner Melbourne) and a handful of others.
But Senator Hanson told Sky News she intends to direct preferences towards some Nationals candidates in tight races elsewhere.
"We're working closely with the National Party in prime seats, we are going to help them get elected, which will balance it out," she said.
The party has not detailed which seats it is looking at.
But while the Coalition is preferencing parties like the Jacqui Lambie Network and UAP higher than One Nation in the Senate in Tasmania, it is preferencing One Nation second in Queensland.
Who is Palmer's UAP preferencing?
Unlike the last election, Clive Palmer has said the UAP will not be directing preferences towards any major party.
It, along with a number of other minor parties with common interests like opposing vaccine mandates, is asking voters to preference major parties last.
But the exact order in which the UAP decides to rank the major parties — even if they are the very last parties preferenced — could still be important.
For example, directing voters to preference the Coalition above Labor in very tight seats like Bass, Macquarie or Chisholm could prove important.
Mr Palmer has said those decisions will be made essentially on a case-by-case basis, possibly with an eye to attacking state governments for their management of the pandemic (like the Labor government in Victoria, or the Liberal government in New South Wales).
Does any of it matter?
How you as a voter direct your preferences can absolutely matter.
Even if you live in a fairly safe lower-house seat, your preferences in the Senate can be really influential.
For example, David Pocock's ambitious bid to take Liberal senator Zed Seselja's seat in the ACT will rely very heavily on preferences.
If he cannot poll more first preference votes than Senator Seselja, he will be relying on preferences flowing from Labor, the Greens and other independents to push him over the line.
But despite all the attention and controversy they generate, big preference deals between parties can have very little consequence.
Clive Palmer's deal with the Coalition in 2019 is a clear example.
Antony Green said the UAP's preferences were not enough to decide any particular race, and did not generally go where the UAP had suggested anyway.
"Most United Australia Party voters gave a second preference to One Nation," he said.
"That's probably because most people never saw that a how to vote card, and made up their own mind."
Who even follows the how-to-vote cards?
And it is hard to know how many voters follow how-to-vote cards, anyway.
Some estimates put it at about 40 per cent for the major parties, so less than half.
And while the Greens will suggest their voters preference Labor, it seems likely that most would preference Labor over the Coalition anyway — so the decision to preference Labor might not mean a whole lot.
Similarly, it is hard to know how many One Nation voters in a seat like Bass (and there may not be many, given they did not run a candidate in 2019) will follow the suggestion and preference Labor over the Coalition.
So the upshot is this; preferences can matter, but preference deals between parties often do not matter much at all.
And nobody can tell you how to vote, it is entirely up to you.
