Back in 2007 Ralf Herbrich and co. wrote a research paper called "TrueSkill Through Time". Their sample code was written with a pre-release of F# 1.0, and was not updated to F# in Visual Studio 2010.

Here is an update of this code for F# in Visual Studio 2010, as requested by some people commenting on that blog entry. Please note that I'm not an expert in the code, and that it does currently require a database connection to use (to save the analysis results)