The ratings of each grade is determined purely from input responses provided by you, the climbing community.

When you provide an answer to "Which is difficult?", the algorithm will update both the grades' ratings accordingly.

The more responses from a wide range of climbers, the more accurate the ratings will be (comparatively to one another of course)!

An invisible component of this each grade rating - sigma - determines the confidence level of the value given to certain grades.

To put it simply, over multiple matchups, the sigma for each grade goes down which indicates a higher confidence level of that numerical rating.

This, in turn, 'cements' the rating of that grade: it becomes harder and harder for it to change rating from future matchups. Ideally, this means that we will arrive at a fixed state of ratings eventually, ceteris paribus.

However, since conditions of gyms gradings can change (e.g. changing setters, different standards, change in business objective), a periodic reset of sigma will be carried out.

As of time of writing , this will happen on 2 occasions: a new year and when adding a new gym to the platform. Such resets wil be termed "Seasonal Resets" and will be reflected on the Rating's Submission front page.

Current algorithm being used is TrueSkills, derived from ELO rating commonly used to rank chess players and eSports athletes.

All feedback, queries or suggestions are welcome!

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