How the forecast works
The forecast doesn't predict one result. It runs the election 40,000 times with slightly different assumptions each time and counts how often each outcome happens. Here is what happens inside one of those runs.
The whole machine
Average the polls
Every published poll goes into a weighted average. A poll counts for more when it is recent (its weight halves every 21 days), has a bigger sample, and comes from a pollster with a good record. Each pollster's lean is measured against the others and removed. For example, Roy Morgan tends to show the Coalition about 2 points lower than other pollsters do.
Check it against history
Polls have missed before. In 2018 they understated Labor by almost 4 points. So the poll average is blended with a "fundamentals" estimate. That estimate starts from Labor's 2022 result and subtracts for a government seeking a fourth term, for Labor also governing in Canberra, and for recent by-election swings. Four weeks out, the polls get 74% of the weight. Here the two agree, so the blend barely moves anything.
Turn the statewide vote into 88 seats
Each seat starts from its own 2022 result. Each party's statewide change since then is shared out across seats. One Nation, which barely ran in 2022, gets more of its vote in rural and outer-suburban seats. That pattern follows where it polled best at the 2025 federal election. The parties it takes votes from lose most in those same seats.
Count the preferences
Victoria uses preferential voting, so a seat is decided by a full count, just as the Electoral Commission would run it. The candidate with the fewest votes drops out. Their votes then pass on according to how that party's voters usually rank the others. This repeats until two candidates remain. The flow that matters most this year is where Liberal votes go once a Liberal candidate is out.
Shake it before every count
Before each run, the model adds random shocks at four levels. They are sized so the spread of results matches how far real seats strayed from forecasts in 2018 and 2022. The biggest is the first: when the polls are wrong, they tend to be wrong everywhere at once.
Repeat 40,000 times and count
Each run produces one parliament. Stacking all 40,000 gives the range of outcomes. The Coalition's median is 39 seats, short of the 45 needed for a majority. That is why a hung parliament is the most likely result.
The 22 October forecast had no poll newer than about two weeks. Newspoll (15–22 October) then put the Coalition on 33, its highest figure in any poll this year. As the freshest poll it carries about a quarter of the weight in the average, and it lifted the Coalition by 0.7 points and cut One Nation by 0.5.
That small shift matters because the Coalition's median sits just below the 45-seat line, where the odds change fastest. Many seats are Liberal v One Nation contests that flip together. Each point the Coalition takes from One Nation is worth about 11 points of majority chance. With an average that reacts more slowly to new polls, the odds would still have risen, to 26% instead of 28%. Most of the jump comes from that sensitivity rather than from overweighting one poll.
The two settings that matter most
Two assumptions explain most of the gap between this forecast and others. Each is shown below at the setting used and at plausible alternatives (12,000 runs each).
When a Liberal is excluded in a Labor v One Nation seat, what share of those votes goes to One Nation?
| Share to One Nation | Labor seats | One Nation seats |
|---|---|---|
| 48% (what RedBridge's respondents say) | 32 | 10 |
| 58% (used) | 28 | 13 |
| 65% (South Australia, March 2026) | 26 | 16 |
The same statewide vote wins more seats if it is concentrated in fewer places.
| Concentration | One Nation seats | Coalition majority |
|---|---|---|
| Half as concentrated | 11 | 36% |
| As modelled | 13 | 28% |
| 1.5 times as concentrated | 16 | 22% |
Rerun on the 2018 and 2022 elections using only the polls available beforehand, the method picked the right party in about 87% of seats. Explore the full forecast, seat by seat, on the forecast page.