The ongoing legal challenge at Brazil’s STF over whether to annul the effects of Anthony Garotinho’s invalidated votes and hold a December second round between Eduardo Paes (PSD) and Douglas Ruas (PL) is the dominant factor shaping probabilities. Ruas was proclaimed governor-elect after the TSE-ordered retotalization gave him 50.88% of valid ballots from the October 4 first round, prompting his transition team to begin security and governance meetings. Paes’ PSD continues pressing its action before Minister Cristiano Zanin, citing voter intent and constitutional majority requirements, while media outlets and some opposition figures have voiced support for a runoff. Traders assign the largest share to “Other,” reflecting skepticism that procedural and timing barriers will be overcome before the December 6 supplemental-election deadline, with any eventual contest viewed as competitive given the narrow first-round gap once Garotinho’s ballots are excluded.