How the Rating System Works

Historical Periods From 1877 until World War One Between the World Wars Post War to the WSC Revolution The Professional Era to the New Millennium The New Millennium and Beyond Other Pages Home Page Article Archive How the System Works Frequently Asked Questions Statistical Points of Interest Current and Future Series Predictions Links Site Map Information for Visiting Webmasters Contact Us Get Free e-mail ratings updates

This page provides a simple overview of the system used.

Introduction

To establish a world ranking for test cricket nations the TCRS has applied a variation of the ELO ratings system.  The system calculates a numerical rating that represents each team's strength relative to other test nations.  When this is applied for all the test series that occur, it produces a stable rating system. As the ratings are a reflection of a nation's relative strength compared to other nations it factors out historical differences such as uncovered pitches versus covered pitches.  This is because nations play each other during various eras under similar conditions (ie, on the same types of pitch and under the same playing conditions). This allows for some comparison between the past and present eras.  There are graphical illustrations of the changes in test cricket ratings divided into five "eras":

Overview of the System

When two nations play a test series their ratings are compared and a "predicted" result is worked out.  At the end of the test series the predicted outcome is compared to the actual result. Note that for the purposes of working out the "actual" result from the series, each team earns half a point for a draw or a tie and one point for a win. If a team does better than their predicted score it is assumed that they have improved and their rating goes up. The converse is also true. If they do about as well as expected then their rating stays about the same. Test Cricketers play to win.  For the ratings system wining by one run or by an innings and one run is immaterial.  A win is a win is a win and they are all treated the same.

Initial Application of the System

At the beginning of the first test in 1877 between England and Australia, each team was allocated an initial rating of 1000 points.  As their ratings were identical the system predicted a drawn result, which happened to be the actual result.  Therefore the ratings remained the same. In the next series, the predicted result remained a draw.  However, the actual result was a win to Australia, hence Australia's rating rose while England's rating fell. By the time South Africa entered international competition, England had reversed the trend and started an early domination of Australia.

Initial Ratings for Subsequent New Nations

Allowing new nations to start with the same initial rating as Australia and England (1000) would distort the relativities within the system.  For example, could you imagine Zimbabwe starting at the same level?  Their rating would merely plummet toward it's current level of 960 odd points as their predicted results would be grossly exaggerated while they were actually soundly beaten by other nations. Therefore, new nations have a raw initial rating worked out by:      -  Taking the average of their opponents ratings over their first 10 test matches; and      -  Making an adjustment based on their level of success during their first ten tests.            -  If a team scored 5 out of 10 then their initial rating is the average worked out above;            -  If their score is less than 5 out of 10 then their initial rating is adjusted downwards; or            -  If their score is more than 5 out of 10 then their initial rating is adjusted upwar

Changes Over Time

The historical graphs on the five eras of cricket give an excellent summary of the performance of the various teams.  It also provides a basis for comparison between the eras.  For example, The Australians under Bradman and Hassett compared to the West Indians under Lloyd and Richards.

If you want more detailed information on how the ratings are calculated get in touch with us at test_cricket_ratings_service@yahoo.com

Last Updated: 8 May 2000