Forgive me if this is a dumb question, or one that has been asked before, but what is the equation used for the "best votes-to-views ratio" option in the unsifted area. Either it's just a simple ratio where the overall order isn't updated often, or it's more complicated than just votes/views.

By the way, I'm by no means complaining, this is nothing more than idle curiosity...

for example, right now it's in this order:
2:5
2:6
2:7
2:9
2:11
2:7
2:8