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 November 30, 2013, to provide some advice on choosing the system parameter tau when the application of the rating system could involve large collections of extremely improbable game outcomes.


    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!