From: Steinar H. Gunderson <sesse@debian.org>
Date: Fri, 5 Oct 2007 21:34:08 +0000 (+0200)
Subject: More writing about FoosRank.
X-Git-Url: https://git.sesse.net/?p=foosball;a=commitdiff_plain;h=8ed5409ab738e8c4fbf30b3279b97c6807802169

More writing about FoosRank.
---

diff --git a/www/index.xml b/www/index.xml
index d645a04..315a7ac 100644
--- a/www/index.xml
+++ b/www/index.xml
@@ -160,17 +160,18 @@
     <h2>About the ratings</h2>
 
     <p>The rating system in use is called <em>FoosRank</em>, and is specially 
-      designed for this system. It is a Bayesian rating system, inspired by
-      Glicko 1 but re-worked out from scratch with a statistically sound model
-      of non-binary results, and adjusted for teams (with some ideas from
-      Microsoft's TrueSkill system). For those not familiar with Bayesian
-      ratings, the most important parts are:</p>
+      designed for this site. It is a Bayesian rating system, inspired by
+      <a href="http://math.bu.edu/people/mg/glicko/">Glicko</a> but re-worked
+      out from scratch with a statistically sound model of non-binary results,
+      and adjusted for teams (with some ideas from Microsoft's TrueSkill
+      system). For those not familiar with Bayesian ratings, the most important
+      parts are:</p>
 
     <ul>
       <li>Your rating is a <em>statistical estimation</em> of your true skill.
 	It has a mean (the point estimate of your skill) and a deviation
 	(measuring the uncertainity of the estimate), called the RD. It is approximately
-	Gaussian (actually logistic).</li>
+	Gaussian.</li>
       <li>When you win or lose a game, your rating will change accordingly,
         based on your score and your opponent. <em>You do not get 'points'
 	for winning or losing, the estimate is merely getting more accurate.</em>
@@ -187,6 +188,11 @@
         you are ranked as an individual, as we do not usually play with fixed
 	teams.</li>
     </ul>
+
+    <p>For the more technically minded, a 
+      <a href="http://home.samfundet.no/~sesse/foosrank.pdf">very rough writeup
+      on the mathematics behind FoosRank</a> is available in PDF format. It is,
+      however, by no means finished.</p>
   </body>
 </html>