What is Ratings Central

Ratings Central is a state-of-the-art, fully automated, online rating system that is very accurate, is open to anyone anywhere, is extremely easy for tournament organizers (event directors) to use, and provides extensive, detailed, accessible information on events, matches, results, ratings, and rankings.

Ratings Central uses a sophisticated rating algorithm developed by David J. Marcus, Ph.D. that fairly and accurately rates all players, from world-class to beginner, from those who compete regularly to those who compete infrequently. The algorithm was originally developed at the request of the United States Table Tennis Association.

The purpose of Ratings Central is to make ratings more immediate and exciting for all table tennis players, while making it as simple as possible for tournament organizers (event directors) to run tournaments and to submit the tournament results for rating.

Most States in Australia have now adopted the Ratings Central system.

All Sanctioned tournament results and Pennant results are submitted to the Ratings Central website for the purpose of calculation of the player ratings.

Rankings vs Ratings

The Ratings Central system is a ‘rating system’ that provides a means of rating players throughout Australia and the World. The system is not a ranking system and is not used by TTACT for the purpose of State Team selection, or for State rankings or for seeding State and Sanctioned tournaments.

You can find all the TTACT ratings (including yours) here

How the Rating System Works

The rating system uses standard concepts and techniques from probability and statistics. This makes the rating system quite different from (and more accurate than) almost all other rating and ranking systems. Detailed information on how the system works may be found from the Ratings Central website.

Zermelo and Cantor

Ratings Central is available for use by anyone and already is being used by several affiliates to create ‘Ratings’ for players in their own pennant competitions.

The following two associated software programs may be downloaded from the Ratings Central website for the purpose of exporting results to Ratings Central:

1. Zermelo
2. Cantor

Zermelo is an excellent program that is used to automate the conducting of a tournament. This program, or the CATTS program, must be used to run either State tournaments or Sanctioned tournaments conducted in ACT. The reason for this is that these programs facilitate the automatic uploading of the tournament results to the Ratings Central web site.

Cantor is a program that facilitates the uploading of pennant style competition results to the Ratings Central web site.

RATINGS CENTRAL GUIDELINES FOR TTACT

These guidelines are to be used by when setting the initial prior for a player new to Ratings Central registered with TTACT.  The initial prior is a term meaning the beginning rating.
Both Table Tennis Australia (TTA) and Table Tennis ACT (TTACT) has adopted the the Ratings Central system, which is an international rating system, for rating players in Australia.  TTACT submits the results of all open and closed tournaments and pennant results to Ratings Central.

What is an Event Director

A person may apply to Ratings Central for permission to submit resuts to the Ratings Central website usually via software downloaded from the Ratings Central website.  That person once authorised is refered to by Ratings Central as an 'Event Director'.

Ratings Central only allows submission of singles events. Ratings Central does not permit the submission of handicapped events. An event to be submitted to Ratings Central must be a a planned and serious event such as a tournament or a pennant competition, 

Rating Points

Each players skill level is described by a rating with mean and standard (plus/minus) deviation e.g. 1350 (+/-50)
Players gain points for singles matches they win and lose points for matches they lose. The mean and standard deviation is recalculated according to the rating of the opponent or the skill difference between the two competitors in each match. It is possible to gain/lose 0 points. The rating is recalculated after each tournament or when matches are submitted to Ratings Central for processing

New Players

From the 1st January 2022 all Event Directors are to assign interim priors for new players according to the ratings bands shown below.  The final rating will be calculated by Ratings Central once the tournament (or pennant) results are submitted and processed.

Ratings Bands

The following ratings bands are based upon the TTACT Pennant Competition by determining the mean of the Ratings Central rating of the players who play in the different divisions.
From the 1st Januray 2022 only the ratings shown below may be applied for a new player to Ratings Central.  Also, please note that the minimum rating that may be applied is 800 +/- 150. (Note - This also applies to new juniors)
Should the initial ratings be set for a value other than shown below then you will be asked to make a correction and re-submit your tournament or pennant competition to Ratings Central.

The following rating bands shall be used for open and closed championships

Minimum Initial Prior - The 500 Floor Rule

This means that the 'floor' as a result of the players initial mean minus 2 standard deviations must be grater than or equal to 500. By following the bands above, this rule will always be satisifed. i.e the floor of the lowest band of 800 (+/- 150) is 500 as 800 - 2 x 150 = 500 

Former Method of Setting the Initial Prior

Previously Event Directors would assign an initial prior based upon their assessment of the new players playing strength in comparison to players that they knew.  This was a very subjective method and was not always accurate.  
When David  Marcus first developed the Ratings Central system, he very quickly realized everyone had differing approaches as to 'who is what standard' and thus has recently advocated a 'large standard deviation' approach to allow results to settle down over time - reducing efforts in judgments and putting more faith into the system. 

For any further questions regarding usage of ratings central please contact Sam Miller at sam@tabletennisact.org.au