Mark Glickman's World

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)


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!