Chess Rating Calculator Changelog

This changelog records five categories of updates: rules profile changes (when a federation updates its regulations and we create a new versioned profile), calculation logic fixes (corrections to formula implementation, rounding behavior, or edge case handling), validation suite expansions (new test scenarios added to the automated verification pipeline), new calculator features (additional modes, export options, or input capabilities), and content updates (significant revisions to educational pages that change the guidance users receive). For implementation details and validation notes, review Methodology and validation.

Cosmetic changes like visual styling updates, performance optimizations that do not affect outputs, and infrastructure changes are not logged here unless they have a visible effect on the user experience.

Each entry includes the date of the change, the affected area (calculator, content, rules profile, or validation), a description of what changed and why, and links to the relevant pages. Entries that affect calculation outputs are flagged with a ‘breaking’ tag so users can quickly identify changes that might explain a difference between an earlier result and a current one.

If you are comparing a result you saved from a previous visit with a recalculation today and the numbers differ, start here. The changelog will tell you whether a rules profile was updated, a rounding behavior was corrected, or a new edge case was handled differently.

A visible, well-maintained changelog is one of the strongest trust signals a calculator site can offer. It shows that the site is actively maintained, that changes are documented rather than hidden, and that users can always trace a difference in output back to a specific, dated change. This is especially important for coaches and organizers who may need to explain to players why a recalculation produces a slightly different result than their earlier check.

The changelog works hand-in-hand with the methodology page: methodology explains how the calculators work, and the changelog explains how that implementation has evolved over time.