Australian Senate Voting Strategies

Australian Senate Ballot Paper

Have you ever wondered:

  • how the Australian Senate voting system works,
  • about easy ways of voting for individual candidates under-the-line, or
  • how to oppose undesirable candidates?

Problem

My analysis of Australian Senate voting has been based on the “Weighted Inclusive Gregory Method”. Unfortunately, I’ve just discovered that the Australian Senate uses the “Inclusive Gregory Method” for counting the votes!

While these two vote-counting methods have a lot in common, they transfer the surplus votes of winning candidates differently – and this can lead to the election of different candidates.

Nevertheless, the weighted method that I have used enables you to (1) understand more about our Senate voting system, (2) get an approximate idea of how much support an individual vote gives to each candidate, and (3) draw conclusions about voting strategies. I suspect that many of these conclusions will apply to both ways of counting in preferential voting elections.

While I’m investigating this, I will leave the rest of this page and the article unchanged with its link to the flawed article and excerpts from the article.

I start this page with some robust strategies for making voting below the line easier, strategies that apply to both methods of vote counting.

Updated 15 Nov 2023

Australian Senate Ballot Paper
Part of an Australian Senate Ballot Paper

The image shows where you can vote for parties above-the-line and where you can vote for individual candidates below-the-line.

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Download an article on Australian Senate voting strategies

(A PDF file: 8,400 words, 33 pages, 684 KB)

Reader’s comments

One reader said, “This is a noble and valuable document and I admire you for tackling this important but tedious subject. We all have a civic duty to be across it.”

A statistician said, “I salute anyone who can make important, complex things very clear”.

Vote for individual candidates, below-the-line.

Voting for individual candidates below-the-line in Australian Senate elections for six senators is the most effective way to vote and can take little effort.

In order to both (1) support candidates you like and (2) defend against candidates that you don’t like, you might only have to investigate and rank six candidates by:

  • viewing the candidates on the Australian Electoral Commission website,
  • viewing the policies presented by perhaps six individual candidates via their personal and party websites, and
  • ranking these six candidates.

The example election I refer to several times was part of the 2022 federal election that Morrison lost, the election in the Senate electorate of Victoria. In this example election, the ballot paper presented 26 parties and 78 candidates. Choosing between the 26 parties above-the-line looks like an easier way to vote, and about 95% of people do vote for parties above-the-line. I voted for parties above-the-line in the example election, but next time I’ll vote below-the-line.

Voting below-the-line can be easier than voting for political parties above-the-line. Strategies to simplify below-the-line voting emerge because, predictably:

  • about 95% of people vote above-the-line, and
  • the ALP and Coalition dominate our politics: in the example election, the Coalition won 2.26 quotas of first preferences and, at the start of counting, immediately won two Senate seats. The ALP gained 2.20 quotas and did the same.

I’ll use some codes:

  • ALP1 = the top ALP candidate
  • ALP2 = the second ALP candidate
  • LNC1 = the top Liberal National Coalition candidate
  • UAP1 = the top United Australia Party candidate

Due to this domination by the ALP and LNC:

  • ALP1, ALP2, LNC1 and LNC2 normally win places 1, 2, 3, and 4.
  • ALP3, LNC3, Green1, and other candidates normally compete for places 5 and 6.
  • You can be confident that one of ALP3, LNC3 and Green1 will win in place 6 or lose in place 7, hold your vote till the end of the counting, and stop the count distributing any part of your vote to lower preferences.
  • If you knew ahead of time which candidates were going to gain places 5, 6, and 7, you would only have to number two of these candidates on the ballot paper to avoid wasting/exhausting any part of your vote and maximise the impact of your vote.

Here are some strategies to minimise the number of candidates you need to investigate and rank:

  • Rank at least 12 candidates: the voting legislation requires this.
  • If these strategies lead you to investigate and rank only 7 candidates: 3 from the big parties and 4 from minor parties, then rank an extra 5 candidates to make up your 12 by ignoring some of these strategies.
  • .
  • Leaving a candidate unranked gives it the lowest rank, together with all the other unranked candidates.
  • .
  • Rank the top candidate of each minor party that you like. Do not rank the lower candidates, as they will not be competitive.
  • Rank the third ALP candidate, ALP3. Leave ALP1 and ALP2 unranked because the count normally elects ALP1 and ALP2 at the start of the count. Other voters will elect them. For a slightly different strategy, see below: “Vote a loser first strategy”.
  • Similarly, rank the third Coalition candidate, LNC3, and leave LNC1 and LNC2 unranked.
  • Rank the top Greens candidate (Green1). Do not rank the lower candidates, as they will not win.
  • .
  • Consider the trio of candidates ALP3, LNC3 and Green1.
  • If your worst candidate is one of this trio then part of this strategy may not be useful to you.
  • If you have candidates that you consider worse than the worst candidate of this trio, then rank each candidate of the trio above your worst candidate. This is a sure defence against the worst candidate. This defensive part of your vote becomes useful in elections where your worst candidate ends up competing for the fifth or sixth seat against one of the trio.
  • Once you have ranked each of the trio, there is no reason to rank, on the ballot paper, any lower-ranked candidate. This is because one of the trio will gain place 6 or place 7, and hold your vote until the end of the count, so the count will not distribute any of your vote to any lower-ranked candidate.
  • I understand that people will be uneasy about giving a preference to a candidate that they do not like, but it is to defend against a worse candidate. Some voters do it. In the example election, Coalition supporters voted defensively for the ALP: 27% of the votes for LNC3 ranked ALP3 ahead of UAP1 and supported ALP3 against UAP1 in the battle for the sixth senate seat. (UAP1 did win place 6, leaving ALP3 in place 7. See more about this example below)
  • .
  • Consider ranking the top candidate in all parties that are likely to be competitive. One indicator of this is the past success of the party. For example, Anthony Green’s post-election analysis of the example election shows that after count 324, the following parties were competing for the sixth and last senate seat: ALP, Coalition, UAP, One Nation, Legalize Cannabis, Liberal Democrats, Australian Justice Party and Derryn Hinch Justice Party.
  • Consider ranking the parties you consider the worst, as two of these might end up competing for the last senate seat.
  • .
  • You might be concerned about ranking candidates you do not like because you do not want to support them against the unexpected success of a candidate you did not rank. Well, on your ballot paper, you can rank all the improbable winners above the candidates you dislike. It’s only more numbering.

Using these strategies strictly, you might have only 3 candidates to investigate and rank: ALP3, LNC3 and Green1. That would effectively defend against all the other parties. However, you’d need to find another 9 candidates to have the required 12 candidates, so here are some strategies to identify extra candidates:

  • Rank other candidates from your liked parties. You do not need to research these candidates because they are unlikely to win.
  • Rank the ALP1 or ALP2, but do not give either your top preference. The section on “Rank a loser first” explains this.
  • Rank LNC1 or LNC2 as just described for the ALP.
  • Rank any candidate below the ALP3, LNC3 and Green1, knowing that your vote will not support these candidates. You do not need to research them.

One big problem with our democracy is how parties choose their candidates and then successfully direct the voters via the party rankings on the ballot paper and above-the-line voting. When voting below the line you:

  • can decide on your own ranking, e.g., Coalition voters might want to rank the Liberal party candidates ahead of the National Party candidates, which would be different to the Coalition how to vote card.
  • start recognising and investigating the individuals you are voting for rather than just the parties.

My ideas are still evolving, and I’d like to hear what people make of this strategy.

Background

In the 2022 Australian federal election, I wanted to vote against several parties, especially one. So, in my vote, I ranked all 26 parties, with my disliked parties at the bottom. Subsequently, I investigated the Senate voting system to see whether this strategy was sensible, and this article describes my findings. It does not advocate for any party or political policy. It suggests you consider using our voting system more fully by ranking the parties you like, and those you dislike.

The article covers:

How the count picks senators

The article considers half-senate elections that pick six Senators for each Australian state. It details how the preferential voting system picks Senators, based on an example from the Australian Electoral Commission website.

How the count spreads a vote

The article examines the example Senate election, showing how the Senate voting system (the count) spread a vote that followed the Coalition how-to-vote card, and the same for votes following how-to-vote cards from the ALP, Greens, and United Australia Party (UAP).

The count always spreads the support of each vote between:

  • the six winning candidates,
  • the candidate gaining place 7, and
  • exhausted votes.

In the example election, the Coalition how-to-vote card ranked the Coalition first, then the UAP, and then other parties. The count spread this vote:

  • 44.6% to place 1: LNC1,
  • 44.7% to place 3: LNC2,
  • 0% to place 8: LNC3,
  • 10.7% to place 6: the UAP top candidate, and
  • 0% to other candidates and exhausted.

The count does not spread a vote beyond that vote’s preference for a candidate or party that gains places 6 or 7. In the above example, the count did not spread that vote beyond place 6, the UAP candidate. The role of the losing candidate in place 7 is surprising as election commentary rarely mentions this candidate.

Strategy: Defensive voting

One voting strategy is to rank only candidates that you like. A disadvantage of this strategy is that you can waste a part of your vote.

You can avoid this waste by voting against the worst candidates, “defensive voting” that ranks:

  • the parties or candidates you like first, then
  • those you dislike, and then
  • the worst.

The article examines eight senate elections to test whether defensive voting is worth the effort.

Coalition voters & defensive voting

In the example Senate election, some Coalition voters seem to have used defensive voting:

  • The Coalition won 2 seats & LNC1 and LNC2 became senators
  • LNC3, the third Coalition candidate Mirabella, gained 275,509 votes, just over half the votes needed to win a seat.
  • Despite his many votes, he lost, gaining place 8.
  • The count distributed his votes between the parties competing for the 6th and last seat: the ALP and UAP.
  • As part of this distribution, the count distributed 10.7% of a Coalition above-the-line vote.
  • This percentage of a Coalition vote was available for voting defensively, either against the ALP or the UAP.
  • Of Mirabella’s distributed votes:
    • 38% went to the UAP, and the UAP won. The Coalition how-to-vote card gave its second place to the UAP and was an effective defensive vote against the ALP.
    • 27% of these Coalition votes went to the ALP. These votes seem like defensive votes against parties like the UAP or Greens.
    • 35% became exhausted and had no say in deciding the 6th seat. Many voters lost their chance to influence this seat.

Strategy: Rank a loser first

Consider the surprising change in the spread of a vote that you can achieve by voting below-the-line and ranking a loser first. Again, consider the example Senate election where:

  • the Australian Unity Party candidate (AUP1) won the 6th senate seat,
  • ALP3 lost, gaining place 7, and
  • LNC3 lost, gaining place 8.

Compare the impact of these three votes:

  • Vote1 ranking: LNC1, LNC2, LNC3, AUP1, and
  • Vote2 ranking: LNC5, LNC1, LNC2, LNC3, AUP1,
  • Vote3 ranking: LNC5, LNC1, LNC2, LNC3, ALP3,

Here is how the count spread the support of each of these votes across the candidates.

CandidateVote1Vote2Vote3
LNC50%0%0%
LNC144.6%0%0%
LNC244.7%0%0%
LNC30%0%0%
AUP110.7%100%0%
ALP30%0%100%

Vote1 was like the Coalition how-to-vote card. It ranked LNC1 and then LNC2, LNC3, and AUP1. This count used 44.6% of this vote to support LNC1, 44.7% to support LNC2 and 10.7% to support LNC3. When the count eliminated LNC3, the count distributed 10.7% of the vote to the Australian United Party candidate (AUP1). I think of this vote as a normal defensive vote against the ALP.

Vote2 modified the Coalition how-to-vote card, using the strategy of giving first preference to a candidate who will lose. It ranked LNC5, and then LNC1, LNC2, LNC3, and AUP1. Vote2 supported LNC5 while the count elected LNC1 and LNC2, so when the count eliminated LNC5, it distributed all of vote2 to LNC3. When the count eliminated LNC3, it then distributed 100% of vote2 to UAP1. I think of this vote as a highly effective defensive vote against the ALP, far more effective than vote1.

Vote3 revolted from the Coalition how-to-vote card by preferencing the ALP not the UAP – and by using the loser first strategy. It ranked LNC5 and then LNC1, LNC2, LNC3, and ALP3. The count treated vote3 like vote2 except that it finally distributed 100% of vote3 to ALP3, not to UAP1. I think of this vote as using “defensive voting” against the UAP and doing it very effectively. All of vote3 went to support ALP3.

These three votes show how a Coalition voter can use the “loser first” strategy to maximise the defensive potential of their vote. Note that, if the Coalition had performed badly, and LNC2 needed support, each of these three votes would have supported LNC2.

The example Senate election shows that some Coalition supporters did rank the ALP ahead of the UAP, 27% of LNC3’s preferences did go to ALP3. If they had voted using the loser first strategy, the count would have used 100% of their vote defensively, rather than 10.7%.

ALP voters can also use this loser-first strategy. It is only a useful strategy for supporters of the two major parties.

(My article details how you can calculate, for a given vote and election, the support that the vote gives to each candidate.)

An ALP vote example

Again, in the example Senate election, if the Coalition candidate Mirabella had won more votes, the ALP could have ended up in 8th place, and the count would have distributed these ALP votes. Votes that followed the ALP how-to-vote card would have had about 8% of their vote available for defensive voting against either the Coalition or the UAP.

An ALP vote below-the-line, using the loser first strategy, would make 100% of that ALP vote available for defensive voting rather than the 8% available to a vote following the ALP card.

Download

Download an article on Australian Senate voting strategies

(A PDF file: 8,400 words, 33 pages, 684 KB)

Your thoughts

I’ve developed these ideas without much interaction and would value your feedback. Some sentences might need clarification, some of my suggestions could differ from your thinking, or you might know of some related articles. Your insight could help refine the article.

I’d also be interested to hear about your strategies for constructing your Senate vote.

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Updated: 15 November 2023 at 2 pm