Glicko Ratings:

 

This web site is intended to provide some background in the theory and practice of rating competitors in games and sports.

Two rating systems I have invented:

• The Glicko rating system, which is in the public domain (document revised Sept 10, 2016, to clarify various aspects of the algorithm)
• The Glicko-2 rating system, an improvement on the original Glicko system. This document has been revised on March 22, 2022, to replace a "<" with "<=" in item 4(b) of Step 5 (page 3).

   

  The Glicko and Glicko-2 systems are in the public domain.

   

  NOTE: As of February 22, 2012 the Glicko-2 iterative procedure ("Step 5") has been corrected and is now stable. Please see the Glicko-2 rating system document for details.

Publicly available Glicko system code/programs:

  (Note: I have not tested any of these implementations, so please use at your own discretion)

• Chess Ranking Assistant, an add-in for Microsoft Excel
• PlayerRatings, an R package implementation of Glicko, as well as a few other rating systems
• pyglicko2, a Python implemenation of Glicko-2
• Glicko2js, a Javascript implementation of Glicko-2
• PHP Glicko2 Lib, a PHP implementation of Glicko-2 (on Github)
• Scala Glicko2 implementation, an implementation of Glicko-2 in Scala (on Github)

 

I applied the Glicko Boost algorithm, which I developed in 2010, to the game outcomes data in the Deloitte/FIDE Chess Rating Challenge.

 

Coming soon (when I find the time!):

• History of common rating systems
• Rating tutorial
• Online rating calculators (including calculators for Glicko and Glicko-2)
• ... and much more!