I really don't understand

Hi @VaDirector,

As previously stated, we cannot disclose any further details on our rating mechanism other than those found in our Ratings FAQ. 

Please also bear in mind the following:

The rating on a title changed even though the total number of votes did not. Can you explain this?

There are several possible explanations for this. First, users are allowed to delete their own votes. So if the rating changes even when the total doesn't, it usually means that some people have deleted their vote while the same number of people have added theirs. Another common explanation is that the weight assigned to votes cast by certain users has changed, so the weighted rating will be affected even when no new votes have been cast.

Finally, please remember that our voting system is always being improved and the formulas used to calculate ratings (and defeat ballot stuffing) are tweaked regularly -- weighted ratings are frequently recalculated, so when the formula is changed the ratings will also change even without new votes.

Thanks!