For each match, the algorithm calculates a match rating and a match weight for each player. A player’s UTR Rating is the weighted average of up to 30 of their most recent match ratings. Only matches within the last 12 months count toward a player’s UTR Rating.
Calculating Match Rating
Two factors are considered when calculating the match rating. The first factor is the UTR Rating difference between opponents. The second factor is the competitiveness of the match, as determined by the percent of total games won.
Given the UTR Rating difference, the algorithm expects a certain percentage of total games won. The player who performs better than the algorithm’s expectation will see their match rating go up while the other player’s match rating will go down. When one player’s match rating increases, the other player’s match rating decreases by the same amount.
Calculating Match Weight
The following factors are used in the match weight calculation:
Format – As the match format increases in length, more weight is given. A match with a three-set format receives more weight than a match with an eight-game pro set format.
Competitiveness – As the UTR Rating difference between players increases, less weight is given. For example, imagine a player with a UTR Rating of 6.00. A match played against an opponent with UTR Rating of 5.00 or 7.00 receives more weight than a match played against an opponent with a UTR of 4.00 or 8.00.
Reliability – As the reliability of the opponent’s UTR Rating increases, more weight is given. A match played against an opponent who competes often and thus has a reliable UTR Rating receives more weight.
Time Degradation – As prior matches get older, less weight is given. Since the algorithm is a representation of current form, it gives more credit to matches played within the last few months.