Voting algorithm: how to calculate rank?

Question

I am trying to figure our a way to calculate rank. Right now it simply takes ratio of wins / losses of each individual entry, so e.g. one won 99 times out of a 100, it has 99% winning rank. BUT if an entry won 1 out of total 1 votes, it will have a 100% winning rank, but definitely it can't be higher that of the one that won 99 times. What would be a better way to do this?

Answer 1

Try something like this:

votes = wins + losses
score = votes * ( wins / votes )

That way, something with 50% wins, but a million votes would still be ahead of something with 100% wins but only one vote.

You can add in an extra weight based on age (in days in this example), too, something like

if age < 5:
    score = score + ((highest real score on site) * ((5 - age) / 5)

This will put brand new entries right at the top of the first page, and then they will move slowly down the list over the course of the next 5 days (I'm assuming age is a fractional number, not just an integer). After the 5 days are up, they will be put in the list based solely on the score from the previous bit of pseudo-code.

Answer 2

Depending on how complicated you want to make it, the Elo system chess uses (or something similar) may be what you want: http://en.wikipedia.org/wiki/Elo_rating_system

Even if a person has won 1/1 matches, his rating would be far below someone who has won/lost hundreds of matches against tough opponents, for instance.