ABSP Ratings
The ABSP have a crazy complicated rating system. I think it's probably similar to chess.
Here's a page describing it, you'll probably need to read it twice. ;o)
In any case, I implemented it in ruby, I think I managed to succinctly implement the concept.
I'm planning to move all the code samples on this blog onto pastie shortly, and also set up an svn repository for them.
