Single Transferable vote
1. You number the candidates on your ballot that you want to get elected, in order of your preference.
2. If there are candidates you don’t want to get elected AT ALL, you don’t put a number next to them.
How it works at the count
1. All the One votes are counted (first preference).
2. The candidate who got fewest One votes is eliminated. (“You are the weakest link. Goodbye!”)
3. So if you voted for that candidate as One, the counters now count your Two vote.
4. All the One and Two votes are counted.
5. And so on…
In the recent party elections, 1330 cakes were baked. Your choices on the ballot were mostly cake parties – strawberry cake for the Red Party, purple cake for the Heather Party, cherry cake for the Green Party, a bundt cake for the Orange Party, and a chocolate cupcake with yellow icing for the Yellow Party. Also standing were a pint for the Beer Party, an apple for the Apple Party, a lollypop for the Lollypop party, and a pair of scissors as an independent.
Only three choices can win.
When you voted, you chose cherry cake as your first preference, scissors as your second preference, strawberry cake as your third preference, purple cake as your fourth, the chocolate cupcake with yellow icing as your fifth, and the apple as your sixth. You don’t like beer, lollypops, or bundt cake.
Single Transferable Cake election
In round one, the apple, the pint, and the lollypop only got 60, 50, and 40 cakes respectively, so they’re eliminated and the cakes baked with Apple, Beer, or Lollypop as a first preference are all distributed to the candidates of their second preference.
In round two, the cherry cake jumps up to 200 cakes – nearly all the apple voters and some of the beer and lollypop voters also liked cherry cake. Most of the Beer voters liked bundt cake for their second preference. Most of the lollypop voters chose either strawberry cake or purple cake as their second preference.
So the scissors are eliminated.
In round three, the 90 cakes that had been chosen for scissors are now re-distributed to their second preferences – mostly either cherry cake, strawberry cake, or purple cake.
So the yellow cupcake is eliminated – even though it had chocolate icing.
In round four, the 101 cakes for the yellow cupcake party will be distributed to their second or third preference choices. A lot of the people who liked yellow cupcakes preferred bundt cake as their second choice, but some wanted purple cake or cherry cake and a few wanted strawberry cake.
But the bundt cake party is now the party with the fewest cakes, because bakers who preferred a pair of scissors, or an apple or a pint or a lollypop, tended not to choose bundt cake as their second or third preference: and not enough yellow cupcake voters wanted bundt cake as their second preference to make a difference.
So by round five, the orange bundt cake is eliminated, and three cakes left.
This ward has now chosen the strawberry cake from the Red Party, the purple cake from the Heather Party, and the cherry cake from the Green Party.
And you have your first, third, and fourth choices from the ballot. In fact, 940 of the 1330 bakers have their first preference choice – a clear majority: of the 390 do not have one of the first preference choices for cake, they may still have at least one of the cakes they chose as a second preference. The main losers are those who wanted orange bundt cake or a yellow cupcake as their first and second preferences and didn’t fancy any of the other cakes at all. Your votes keep being counted so long as you’ve expressed a preference for a cake still on the counter at each round.
The goal is for most people to get at least one cake that they’re happy with.
PS: For a more serious explanation (without cake) see Electoral Reform Society.