Rating calculators introduction


The various online rating calculators provided on my website are derived from two C++ classes CRatingBase and CRatingTables. The first one provides an interface for storing results, player information (f. i. age) and statistical calculations per player, and the second one provides several tables for calculating success and rating differences. From this base most rating algorithms are easy to implement, even if the tend to be a bit complicated as with the German national rating DWZ. Some algorithms require knowledge of a complete tournament (f. i. the first DWZ rating) for iterative calculations. Therefore a tournament layer has to be added in future. I began to develop it years before I planned a website simply for better understanding of different rating systems. This is the reason why I use C++ and fetch the results via AJAX requests from the server. For the web a client side calculation in JavaScript would be much more appropriate of course.

A lot of organizations publish their rating rules, but most of them do not provide test data. This is especially a problem with special rules for initial ratings and rocket players (those who have huge success compared to their current rating). And I detected tiny differences simply by using different compilers (Visual C++ and gcc).

Currently the following calculators are available:

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