A record number of candidates and parties are contesting the Victorian election, increasing the odds of little known micro parties being elected.

But which parties make the final cut could depend on the complicated preference deals being done between them.

ABC election analyst Antony Green believes roughly eight minor party candidates could be elected to the Legislative Council, partly because of the daunting number of candidates on the Upper House ballot paper.

He said it made it more likely people would vote above the line for a single party, rather than preference individual candidates.

"And then preference deals come into play," he said.

"It raises the prospect that someone nobody's every heard of could get elected.

"It's absolutely certain that no major party will control the Upper House. But the composition of the crossbenches is difficult to work out."

How does it work?

Unlike in the Lower House, where Victorians vote for a single local member to represent them, in the Upper House people vote for five members to represent their larger geographical region.

Upper House 8 regions

8 regions 40 MLCs elected

40 MLCs elected 21 parties

21 parties 351 candidates

Victoria's legislative council is made up of eight regions, three of those in country areas.

This year, the number of parties contesting the election has doubled to 21 while the number of candidates contesting the Upper House has increased by 70 per cent, to 351.

Alongside better known minor parties such as the Australian Greens and Palmer United Party, moral conservative parties like Family First and Rise Up Australia are contesting, as well as libertarian parties such as the Sex Party and single issue parties such as the Voluntary Euthanasia Party.

Mr Green said he believed the Greens would retain at least three seats in the Upper House and perhaps win more.

"Realistically, the minor parties can only win one seat in every region, though in Northern Metropolitan there would be the chance of both a Green and a minor party [candidate] getting elected," he said.

Voting in the Upper House

In Victoria, a single vote above the line will see preferences flow to candidates in an order specified by the party the person has voted for.

The alternative is to vote below the line for the candidates of choice.

Unlike federal elections, Victorian voters only need to number five boxes below the line.

"If they don't want to vote above the line for a party [because] they don't trust how parties distribute their preferences, when they fill in below the line ... they only have to fill in five preferences," he said.

"They can go beyond five, but they don't have to fill in every square.

"You don't have to feel daunted."

He said the more voters who make their own decision on preferences by voting below the line, the less influence the party preference deals will have.

Parties negotiate preference deals

Unprecedented preference deals are being done in Victoria this election.

The Greens have attracted criticism for preferencing Clive Palmer's Palmer United Party above Labor in some Upper House regions, despite the party's ideologies being largely opposed.

Similarly, the PUP has preferenced the Greens above Labor and the Liberals in some seats.

The Shooters and Fishers Party has secured the second preferences of several parties, including the Liberals, in the Eastern Region which covers Gippsland.

Conservative party Rise Up Australia will also benefit from the second preferences of several micro parties in the South-Eastern Metropolitan Region.

However, Mr Green said it was near impossible to work out how all the preference deals would all work out come election day.

"This is what's wrong with the system," he said.

"If someone like me, who knows it very well, has difficulty working out where the preferences will flow, then how can the average voter possibly understand the ticket voting system?

"This is what micro parties thrive on."