A player's Collins Rating is a number determined by their play history. A higher number generally means they have had better past results. Players' ratings are a measurement and do not affect normal league or tournament standings. Ratings are adjusted based on the results of each match in normal leagues and most tournaments. At the hosts' discretion, tournaments can use the players' ratings to seed tournaments.

The details on how ratings are calculated are available here. In lay terms, the ratings of the two players in match are compared before the match begins to determine an expected result. This expectation is compared to the actual result in the match, considering rounds won/lost/tied. If the expectation matches the result, no rating adjustment is made. If the expectation varies from the result, an adjustment is made to the players' ratings to more closely align the next expectation with the result. This means the rating is self-correcting.

The ratings can be a useful measure of progress relative to the players in ones league. They are a useful measure for comparing relative skill.

The rating should not be viewed as "points", it is a relative measure. If the difference between two opponents ratings creates an expectation that the higher rated player should win all three rounds and they win only two rounds, the higher rated player's rating will be adjusted down and the lower rated player's rating will be adjusted up. Essentially, the players are more evenly matched than their original ratings predicted.

Won rounds always count positively into a player's match result. Rounds tied at 27 never count negatively into a player's match result. Tied rounds can contribute negatively if the player was expected to win more rounds than they did.

Assuming the 2-1-0 point system is referring to how league seaon standings are determined, these two serve different functions. The 2-1-0 system generates the standings for a particular season. CRS offers a continuity over a player's career and is more nuanaced because it considers not the match result, but round results.

At a tournament host's discretion, tournaments can use the players' ratings to seed tournaments. While this isn't a common practice to date, it has been used for this purpose.

Currently, since there is no match view for playoff and tournament matches, we cannot. This match view will be introduced in a future update.

Calculation of rating adjustments for playoff matches and regular league season matches is the same up to a weighting factor. Playoff matches are weighted 20% higher than regular season matches to reflect the increased stakes. Playoff rating adjustments are still based on the difference between the match expectation, derived from the players' starting ratings, and the match result. The weighting means that when adjustments are warranted, they move the players' ratings a little more.

The top 300 rated players are numbered. Below that number, percentile is used to indicate standings.

Calculation of rating adjustments for tournament matches and league matches is the same up to a weighting factor. Tournament matches are weighted the same a playoff matches or sightly higher, depending on the size and scope of the tournament to reflect the increased stakes, and to encourage normalization of ratings between players that don't often compete. Tournament rating adjustments are still based on the difference between the match expectation, derived from the players' starting ratings, and the match result. The weighting means that when adjustments are warranted, they move the players' ratings a little more.

There are no current plans to use CRS in this way, though the concept has been raised in discussion internallly at the IATF, as well as with IATF members and in community feedback.

In a normal league match, a difference in opponents' ratings of greater than 636 creates an expectation that the higher rated player will win all three rounds. If the higher rated player does win all three rounds, no adjustment is made to either players' rating.

No, since CRS v1.2 (which dates back to 2020), ties at 27 never count negatively for the higher ranked player. Ties at 27 represent the only secanrio where players' combined adjustment is not zero. Meaning, it is possible for a both players to be adjusted upward or for the absolute value of one player's adjustment to be unequal to the other's.

The math to support the calculation is here. The code implementation is not open-source.

Players who have been inactive for over are year are not displayed in the lists.

Currently the rating on player profiles is their Standard Rating. Premier Ratings will be added in a coming update. Big Axe matches are in the recreational category and do not produce CRS adjustments.