Every vote has to count to someone... so you can't have a "dead end" on a ballet (hence a vote isn't counted if it isn't filled out completely). They preferenc

Every vote has to count to someone... so you can't have a "dead end" on a ballet (hence a vote isn't counted if it isn't filled out completely). They preference all 100+ rankings, but do it by groups (generally). i.e. Party A will preference Party B candidates, then Party C. Though some smaller parties do very individual preferences.