Wikipedia
The Playmander was a pro-rural electoral malapportionment in the Australian state of South Australia, introduced by the Liberal and Country League (LCL), in place for 32 years from 1936 to 1968. It consisted of 26 low-population rural seats holding up to a 10-to-1 advantage over the 13 high-population metropolitan seats in the state parliament, even though rural seats contained only a third of South Australia's population. At the peak of the malapportionment in 1968, the rural seat of Frome had 4,500 formal votes, while the metropolitan seat of Enfield had 42,000 formal votes.
Additionally there was a change from multi-member seats to single-member seats for the first time in South Australian history and the number of MPs in the lower house was reduced from 46 to 39. With a decisive advantage to the LCL, voters may have been more inclined to vote for the expected status quo LCL government.
Labor managed to win enough parliamentary seats to form government just once during the Playmander against the odds − in 1965. Labor won comprehensive majorities of the statewide two-party vote whilst failing to form government in 1944, 1953, 1962 and 1968.
More equitable boundaries were subsequently put in place following the 1968, 1975, and 1989 elections. More seats were introduced, and seats were required to be proportionate, as well as having a unique fairness clause which directs the Electoral Commission of South Australia to redraw boundaries after each election with the objective that the party which receives over 50 percent of the statewide two-party vote at the forthcoming election should win the two-party vote in a majority of seats.
One element of the Playmander remains to this day − the House of Assembly is still elected using single-member seats. Prior to the Playmander, the House of Assembly had always been elected using multi-member seats since the inaugural 1857 election.