Every user can rank the stories however they want. If one story receives the majority of first places in the first voting round, it will be declared the winner. If not, it begins removing the lowest ranked stories across the board and redistributing the votes from them until we reach a round where one story receives the majority of highest placements.
World Enough/Doctor Falls is currently the winner after one round, because it has received three first placements, one fourth place and one tenth place, and it has therefore a majority of first placements. As opposed to Parting of the Ways and Journey’s End, both of whih have only one first place.
This system is also used to determine the winners in the Academy Awards, by the way.
This was tricky. I had all the Doctors already in a ranked list in my files, but not the season finales, so I had to consult the graphs for this one. I’m sure there will be nothing controversial about my picks in any way. /j