Tasmania's unique Hare-Clark voting system could see up to four sitting parliamentarians lose their seat to candidates from within their own parties on Saturday.
Big vote winner Adam Brooks looks likely to be returned to the House of Assembly at the expense of Felix Ellis, while across in Bass, high-profile Labor candidate Janie Finley could replace running mate Jennifer Houston.
Mr Brooks has once before replaced a sitting member from his own party, having ousted Brett Whiteley in the 2010 election.
Labor's left faction fears about candidate Dean Winter are likely to be realised after the weekend with the Kingborough mayor likely to take his seat in the house over Alison Standen.
In Lyons, Liberal candidate Susie Bower could possibly replace Liberal MHA John Tucker.
The Hare-Clark system pits candidates within parties against each other in the pursuit of the most primary votes.
Political analyst Richard Herr said if a parliamentarian was to lose their seat, they'd more likely lose it to a fellow party member.
"The history of Hare-Clark is that between two-thirds or three-quarters of all of the changes in parliamentary representation have been losses within a party rather than between parties," he said.
Professor Herr said this was because a ballot was a single transferrable vote, not a party-list system.
"So the vote goes where an elector wants it to go," he said.
"This has been protected by preventing parties from issuing how-to-vote cards.
"A lot of this goes back to Andrew Inglis-Clark's inherent liberalism."
Along with his support for the single transferrable vote, Inglis-Clark supported multi-member districting so electorates had diverse representation.
"This meant it would be very, very difficult for one constituency to be represented by a single party," Professor Herr said.
He said the system of a single transferrable vote and multi-member electorates meant preferences were a big deal.
"In a period where the rusted-on voters have declined from 68 per cent to 44 per cent, preferences are more fluid and unpredictable than any time in the past," Professor Herr said.
"This has had the effect of elevating personalities over party ideology."
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