The point system is easier to explain if each unselected spot transform into a star that flies to the point counter.
I saw that it also made its way onto Metafilter - did you by any chance have anything to do with that?
Nothing in particular, but if in few months you have some time, it may be interesting to read a blog post with more details. There are many details that no one realize until they try to write the code and that is usually a good starting point for a good blog post.
(As an example, I thought about the "same year" rule. But you probably have a rule to try to balance military and sport events, and perhaps more...)