In the early days of polanoid.net, SotD was simply the picture that had the highest number of votes at 1:23 AM (CET) every day (night).
But soon it turned out that when just counting votes like that, always the same *popular* people won and I tried to create a "vote-weighting" algorithm that should guarantee also winning chances for less known/seen pictures as a reaction to the growing unhappiness and resentment of users who said (rigthly to some degree) that SotD has nuffin to do with picture quality but is only a "mere popularity contest
The rather complex algorithm, that was in use for almost 9 months now, weighted each vote according to different factors of the voter (total number of different pictures the voter has seen) and the owner of the picture that is voted for (how "popular" is the person, how many times has the person won SotD before, how many days have passed since the last win,...) and also the ratio of votes and "distinct picture views" (how many different users have seen a picture - the "Views:" number in brackets in the infotab of a picture).
The whole idea was
to have a bigger variety of people on the cover and above all, to make the process more fair
also for less popular, less "seen" pictures and users.
Now since the confusion about this process and the criticism that the calculation is too esoteric and unsearchable, not transparent at all - I have been rethinking the whole process and it's inital motive and now came up with a new, much simpler calculation, which I think couldnt possibly be more fair and reasonable and hopefully will keep everybody satisfied.
the new process is rather simple:winner is the pic that has the highest vote *ratio*
, expressed as the percentage of votes per distinct views.
a rather simple and straightforward approach, cause only people who have *seen* a picture can *vote* for it.
so if 20% of all people who have seen a picture voted for this picture, it will win over a picture that only 5% of viewers have voted for - even if the 20% may be only 5 votes as compared to the maybe 20 votes of the pic with the 5% vote-ratio, if the picture is the one of a very "popular" person.
(you might select "order by votes" when viewing all pictures and look at the numbers of votes and distinct views to get an impression)
So to keep the whole process transparent and to satisfy the often expressed wish to reveal the exact algorithm - here is what happens every night (CET) at 1:23 ...
||the 250 pictures with the highest numbers of votes (10 votes minimum) at this moment are chosen for further calculation.
||for these pictures the votes per distinct views ratio is calculated >> (votes/distinct views) *100
(=36.36% for today's SotD)
||in case of equal rank, the net number of votes is taken into consideration.
||in case of still equal rank, the system flips a coin (random number generator decides).
Unlike in the previous algorithm, no further vote adjustment is made, no matter how often the user has won before, no matter if he won just the day before.
the only thing that counts is the votes/distinctViews ratio, which should eliminate all "popularity" concerns.
If anybody has a better/more fair idea, or finds any logical flaws in this algorithm, please tell me so, I'm open to suggestions.