r/Brazil

I ran a historical/mathematical analysis of Brazil’s presidential runoffs rather than just looking at headline polls.

First, the historical fact: under Brazil’s current two-round presidential system, the candidate who finished first in the first round has never gone on to lose the runoff.

That would normally favor Flávio Bolsonaro, who finished the 2026 first round ahead of incumbent President Luiz Inácio Lula da Silva, roughly 47% to 45%.

But the historical percentage movements between rounds tell a more complicated story.

My analysis looked at 4 things:

1. First-round top-two normalization

If you simply remove all eliminated candidates and normalize only Flávio and Lula’s first-round votes, the starting point is roughly:

Flávio Bolsonaro: 51.3%
Luiz Inácio Lula da Silva: 48.7%

So on pure first-round arithmetic, Flávio begins with about a 2.6-point normalized advantage.

1. Third-party voters

Only about 8% of the first-round vote went to candidates outside the top two.

That is important because 2026 looks much more like 2022 than elections such as 1989 or 2002, when huge portions of the electorate had to redistribute between rounds.

The relevant 2026 third-party bloc includes voters who backed candidates such as Renan Santos, Augusto Cury, Ronaldo Caiado and Romeu Zema.

These voters are not one ideological bloc.

Caiado and Zema voters would reasonably be expected to lean more toward the Bolsonaro side based on their political positioning, while other minor-candidate voters are more mixed. Some will also abstain or vote blank/null rather than move cleanly to either finalist.

That means simply assigning the entire third-party vote to Flávio because several minor candidates are on the center-right would overstate the transfer.

1. What happened to third-party voters in previous runoffs

Historically, the first-round leader’s normalized top-two share often falls in the runoff.

1989: -10.9 points
2002: -5.4 points
2006: +7.0 points
2010: -2.9 points
2014: -3.7 points
2018: -6.0 points
2022: -2.0 points

The important comparison is 2022.

The third-party pool in 2022 was about 8.4%. In 2026 it is about 7.9%.

That makes 2022 the closest modern historical comparison by pool size.

Applying the 2022 redistribution mechanically to 2026 takes the first-round leader from 51.3% normalized to roughly 49.3%.

1. Incumbency

There have been only 3 direct cases in the modern runoff era where a sitting Brazilian president personally reached the second round:

Lula in 2006
Dilma Rousseff in 2014
Jair Bolsonaro in 2022

All 3 increased their raw vote percentage between rounds.

Using the top-two normalized comparison, the incumbent shift was approximately:

Lula 2006: +7.0 points
Dilma 2014: -3.7 points
Jair Bolsonaro 2022: +2.0 points

The median incumbency effect is therefore about +2 points.

The most structurally similar case is actually 2022, because Jair Bolsonaro was the sitting president and entered the runoff in second place — exactly where Lula is now.

When I apply that approximately +2-point incumbency effect to Lula’s current normalized starting point of about 48.7%, the model lands almost exactly here:

Luiz Inácio Lula da Silva: 50.6%
Flávio Bolsonaro: 49.3%

That is my final projection.

Why could I be wrong?

The biggest reason is the historical fact I started with: no first-round presidential leader under Brazil’s current system has ever lost the runoff.

The second problem is that this is a tiny historical sample. There have only been 7 presidential runoffs, and only 3 involved an incumbent president.

Third, voter transfers are not mechanical. Someone who voted for Caiado, Zema, Cury or Santos is not obligated to behave like a similar bloc from 2018 or 2022. Endorsements, campaign events, turnout and abstention can change the result.

Fourth, Flávio begins with a real first-round advantage. If the center-right third-party vote consolidates behind him more strongly than my model assumes, the result changes quickly.

So the historical precedent points one way, while my percentage-transition model points narrowly the other way.

My final projection:

Luiz Inácio Lula da Silva — 50.6%
Flávio Bolsonaro — 49.3%

Bolsonaro is extremely likely to win after all of the second round polls have just released. I read that all of the voters of the 3 candidates who got over 2% will all vote for Bolsonaro. This is horrifying. Bolsonaro will greenlight Amazon deforestation so bad that it will affect the entire world's atmosphere. We all rely on the Amazon rainforest for oxygen. Without it, we don't breathe. How could Brazil vote against its own supplier of oxygen? Vote against nature??

Hi r/Brazil,

I've made a new guide (updated from my last 2024. guide) on How to get a CPF as a Foreigner.

I've added FAQ, some custom buttons and contributions were mentioned from other redditors that helped me write this blog post. Also, online method is unfortunately no longer available as stated on the gov website so make sure to take that into account.

AI is used strictly for featured images and website visuals, content in my blog posts is always 100% human-written and checked by me various times before publishing.

I hope you find this guide useful and I'm open to suggestions/changes for both the website and my current/future blog posts.

Have a nice weekend.