Ranked ballots area a way to ensure that all MPs need at least 50% of the votes to be elected.  Also called “preferential voting” or “alternative vote”, the ridings remain the same and have one MP each, and the ballot paper looks like it does now, but instead of putting an X in the circle next to the name of one candidate, you put the number 1 next to your first choice, 2 next to your second choice, 3 next to your third choice, and so on.

The counting method is called “Instant Runoff”.  It starts like it does now:  the ballots get put into piles according to which candidate has a “1″ next to their name.  These are the first choices of each voter.  When all of the “1″ marks have been counted and added up for the entire riding, if one candidate has over 50% of the valid votes cast, he or she is declared the winner.  If not, the candidate having the fewest votes is eliminated and the valid second-choice “2″ marks of that candidate’s pile are counted and added to the already-counted votes of the other candidates.  This continues, eliminating the remaining candidate having the fewest votes, and counting the second-choice candidates of those ballots (or the third if the second is for a candidate that has already been eliminated) until one of the candidates has over 50% of the votes.  When you get down to two candidates, it is certain that one of the two will have over 50% of the vote.