Mark that is my point. I understand Brian's theory. However it is flawed because each song must have the same amount of fair judgements for the system to be fair. Put another way a song with few contests voted on the same has lost potential votes to boost it or lower it so it has little chance of moving. A song that has more contests has a greater chance of picking up votes whilst neither gaining or losing ground if votes are cast the same.

I think the system is based on percentages. If a song has a higher percentage voting it better than another song then it moves to one above that position. Therefore positions are constantly changing. even this system cannot be completely fair as some songs get more contests or only contests against the lower ranking songs whilst others come against the top or have fewer contests. Just to throw another spanner some people only judge a few contests anyway. How does that affect the judging.

http://www.soundclick.com/bands/songInfo.cfm?bandID=687727&songID=5238055