Information for Event Directors

This page explains how to become an event director and submit events to Ratings Central. If you are looking for software to help you run your tournament, you can also find Zermelo here.

Rating Scale

In order to be a Ratings Central event director and submit events to Ratings Central, you must have an understanding of the rating scale that Ratings Central uses. In other words, you must know what it means to be a “1500 player” or a “2000 player”, and you must be able to watch a player playing a match and estimate their level to within a few hundred rating points. To assist you in understanding the rating scale, we have provided videos on the Videos of Players of Various Levels page. Also, see the discussion of how the Ratings Central rating scale relates to the USATT rating scale on the Priors for Unrated Players page.

Submitting Events

There are four ways to submit events to Ratings Central. You can use Cantor, Zermelo, Gerard McCarthy’s RCPennantSubmitter, or your own software.

Both Cantor and Zermelo are Windows apps that you run on your own PC. (There is no Web form for submitting events because Cantor is much easier to use than a Web form.) System requirements are any computer running Windows 11, 10, 8.1, 8, 7. If you have a Mac or Linux, you’ll need Wine, CrossOver, Parallels, etc. (Or, you can buy a Windows computer.) For Zermelo, you’ll need a printer.

To submit events, you will also need an Internet connection. You do not need to be connected to the Internet while the matches are being played, but you will need to be connected when you are ready to submit results to Ratings Central.

Cantor’s sole purpose is to let you record results and submit them to Ratings Central. Cantor can be used with any event that you run, regardless of its format.

Zermelo’s purpose is to make running table tennis tournaments simple. Zermelo is the premiere software application for running table tennis tournaments. It handles all aspects of running a tournament, including submitting the results to Ratings Central. Zermelo also has support for running USATT-sanctioned tournaments. While Zermelo can handle most of the popular tournament formats, it cannot handle all formats. Cantor is easier to learn than Zermelo is because it does less.

For more information on Cantor and Zermelo, please download and run the setup programs. Each setup program installs the application and the user’s manual. You can also download the user’s manuals separately, if you want to look at them without installing the applications.

Gerard McCarthy’s RCPennantSubmitter is designed to submit pennant scores to Ratings Central. It also does pennant fixturing and ladders.

If you have been using your own software or a spreadsheet to run your event, and want to continue to use it, please and ask for the “API documentation” to find out how you can interface your software to Ratings Central.

Before using Cantor to submit events, you must read the Cantor User’s Manual. Before using Zermelo to submit events, you must read the Zermelo User’s Manual. Before using anything other than Cantor or Zermelo to submit events, you must read the Cantor User’s Manual because it contains important information about the procedures that you must follow.



If you have a previous version of Cantor or Zermelo installed, you do not need to uninstall it before installing the current version.

Registering as an Event Director

Before you can submit any events to Ratings Central, you must register as an event director. To do this, click the “Register as an Event Director” link at the bottom of this page and fill out the form. We will let you know via email (within one day) when we have activated your account.

Once we activate your account, you will be able to use Cantor and Zermelo to submit results. You will also be able to use the Ratings Central website to download a rating list (that includes player postal and email addresses), download a club list, update your director information, add or modify club information, update player information, and associate players, directors, and events with your clubs. To do any of these things, simply log in by clicking the “Event Director Support” link that is on every page in the left sidebar under the ads. When you are ready to run an event, you will want to download a rating list and a club list for importing into Cantor or Zermelo.

Note that you do not need to register as a Ratings Central event director if all you want to do is use Zermelo for an event that you will not be submitting to Ratings Central.

Event directors are responsible for making corrections (including removing duplicate players) for any events that they submit. Such corrections may be necessary long after an event is submitted. Therefore event directors are expected to back up their database files and retain them indefinitely. Event directors should reply to emails within one business day and fix problems within one week.

Director IDs may not be shared. Each person who submits events must have their own director ID and is responsible for the events that they submit and for retaining, maintaining, and preserving the database files for those events. You may transfer your director ID to another person by giving the other person the database files and updating the information for the director ID to be that of the other person.

Event Minimum Requirements

It is up to you what events you submit, but here are the minimum requirements:

You do not have to use Ratings Central ratings for seeding or eligibility, but of course, you are welcome to.

Unrated Players

Before running an event, please read about assigning priors for unrated players. This explains how (and when) you should specify means and standard deviations for unrated players who play in your events. Besides being available by clicking the link, this information is also in the Cantor and Zermelo user’s manuals.


See Cost for how much Ratings Central and Zermelo cost.

Registration Link