Bruno´s rationale is incorrect.
Voting for Marina does not increase the chances of a second round, that is for sure. Because u are atomistic, you dont influence the results.
Voting for Marina to increase the chances that Dilma ends up being defeated does not make any sense either (even if Marina is more likely to defeat Dilma than Aécio is). For the same fucking reason: u are atomistic and 1 vote counts shit.
Better: vote on who you like the most, not because of strategic reasons. Your vote counts shit (sorry for the stark realism)
My name: Economist X
My mission: Deliver thee from Evil
Dont trust anyone, trust only me.