A Plan for Pepperoni

Here is a table of how the voters rank the different choices. You are one of the two voters in the first column.

 P S A M S M P A M P S S A A M P
Now imagine that you know the other voters' ranking in advance. In this simple case you may simply know your friends' preferences in pizza. In national and statewide elections there are usually polls which are published in advance which give a pretty accurate view of how people will vote. In Congress, the political parties have leaders whose job it is to count how their members will vote on each bill - the outcome is usually known in advance.

What is the outcome if the plurality method is used? Clearly, anchovies win with 4 votes. This is bad for you. Is there anything you can do about it?

Suppose you and the other voter represented in column one decide to switch your vote to sausage. (The two of you really prefer pepperoni but you each cast an insincere vote for sausage.) What happens?

Now sausage gets 5 votes and beats out anchovies which has only 4 votes. You don't get your first choice, but you are able to manipulate the election to get your second choice - and sausage is a lot better than anchovies to you.

Of course once we go down the road of insincere voting, things can get pretty complicated.