If a player has only one match at the championship then the weighting is currently 80% the Final Dynamic and 20% the rating from his one match.

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1 About the NTRP Rating System: The NTRP rating system is very complex. In order to understand how this works many terms must be defined. Every industry has a terminology all its own. Sports are the same; baseball has the homerun, football has the touchdown, tennis has the drop shot. The rating system also has terms which need to be understood so that we can understand what is being said. The following should help you to understand how the rating system works I hope. Benchmark Rating: The term "benchmark" will be used throughout these procedures. It means a player whose rating has been determined by the computer using a combination of the dynamic rating for a player and their match results and to whose record other records are compared, directly or indirectly, to derive ratings for a large number of players. Generally speaking, players who participate in USTA League Tennis National, Section and Area Championships and disqualified players are benchmarks. Any player who advances beyond the local league becomes a Benchmark player. Benchmark players are assigned a rating which is an average of their Final Dynamic Rating and their Match Ratings at the championship event to which they progressed. If a player has only one match at the championship then the weighting is currently 80% the Final Dynamic and 20% the rating from his one match. If a player has two matches at the championship then the weighting is currently 60% Final Dynamic and 40% the match ratings from the championship. If a player has three or more matches at the championship, then the weighting is currently 50% for Final Dynamic and 50% for the match ratings from the championship End of Year Benchmark ratings can not be appealed in the 2009 league year. If the player does not generate a new rating during 2009, then the 2008 benchmark rating may be appealed in Rating Appeals: For a computer rated player who is eligible to appeal his/her rating, there is the borderline appeal. Borderline for those less than 60 years of age is.05 which means a 4.05 rated player may appeal down to the 4.0 level. In addition; a 3.45 rated player may appeal his/her rating up to the 4.0 level of play. The borderline for players who are 60 years or older is.10 which means that a 4.10 rated player may appeal his/her rating down to the 4.0 level of play, and a 3.40 rated player may appeal his/her rating up to the 4.0 level of play. The borderline appeal is solely done by numbers. There is no committee that reviews any information on the appeal. The Medical Appeal can only be used for a condition that has occurred after the last match played by the player that was used in calculating the player s rating. This means that if the player was injured after the ratings were calculated the injury may enable the player to file a successful medical appeal. However, if the player had the injury when playing any of the matches that went into the calculation of his/her rating, then the medical appeal will not be successful. All medical appeals are now processed by the

2 National Office of the USTA. Appeals are still submitted through the District/Section Office, but the decision on medical appeals is made by the National Office. Top of Level: Benchmarks have ratings indicated in hundredths of points that may be any rating (e.g., 3.33, 4.14, 4.78, 5.01, etc.). Players identified as being at the top of an NTRP level (3.5, 4.0, 4.5, etc.) should not be referred to as benchmarks (unless they are benchmarks as described above). To eliminate any confusion, these players should simply be called top-of-level. Dynamic Ratings: The term dynamic rating refers to ratings that the computer assigns based on play during the current league year. New players to the system have an initial dynamic rating assigned when they play their first match against a player with a computer rating. The initial dynamic rating for players with a published rating is their previous year-end rating in hundredths of a point. The Final Dynamic Rating is the regular daily ratings which are calculated as matches are played during the year. But for Year-End calculations we also include matches in addition to those from Adult League and Senior League. Depending on the Section this could for instance be COMBO and Super Senior and Tournaments. Procedures for Calculating Dynamic Ratings for Players who have computer ratings: In matches where all players, have previous computer ratings, the procedure is: 1. System checks current dynamics of all players involved. 2. System looks up likely score outcome from a comparison table. 3. System compare likely match score with actual score, and a larger than expected winning margin increases the winning team s ratings and decreases the losing team s ratings by the same amount. A smaller than expected winning margin decreases the winning team s ratings and increases the losing team s ratings by the same amount. If the underdog wins (according to the comparison chart) their rating will increase markedly. The rating of the favored team will decrease by the same amount. 4. System generates the new current dynamic rating by averaging each player s rating obtained in #3 with their previous three dynamic ratings. Procedures for new players without a current dynamic are computed by several different algorithms depending upon how many matches they have played against players who do have a current dynamic rating. 1. The very first dynamic rating of a player is calculated using the rating of his/her opponent and the closeness of the match using the comparison chart. 2. The second dynamic rating is calculated using the rating of his/her opponent and the closeness of the match using the comparison chart. 3. The third dynamic rating is calculated by averaging the two existing dynamics together and comparing them to the rating of the opponent(s). Then it looks at the closeness of the match to see if it agrees with the compared ratings. On the basis of that, the rating of the new player is calculated.

3 4. The fourth dynamic is calculated like the third but all three previous dynamics are average together first. 5. From this point on, the rating of the player is always their most recent dynamic averaged with the previous three dynamics. Timeline for End of Year Ratings: The rating system has a standard way in which it operates. This system includes certain things that happen at certain times throughout the year. The following timeline should help you to understand a bit about how the system operates. 1. League starts and Dynamic Ratings are calculated as the matches are input into the Tennislink Data Base. The initial dynamic ratings for computer rated players are the end of year ratings from the previous year. So for the start of the 2009 USTA League each player s end of year 2008 rating will be his/her initial dynamic rating. 2. The Area, District, and Sectional Championship match data is entered into the system in a separate section as each event occurs. 3. After the Sectional Championships all additional data that will be used in the end of year ratings is identified data such as NTRP Tournament Matches. 4. After the National Championships the National Benchmarks cascade down through the Sectional, District, and Area Championships to generate additional benchmarks. 5. The benchmarks are then used to generate the computer ratings in the local league. The final rating for computer rated players (those who are not benchmarks) is their benchmark-derived computer rating. 6. Ratings are then published (about Thanksgiving Time for the Missouri Valley) Disqualification by Dynamics: In 2008 players with computer ratings and players who self-rated into the system were subject to DQ (disqualification) by Dynamics. A player would be DQed if he/she was Clearly Out of Level. Clearly Out of Level is defined by the following numeric chart based upon level of play and the player s dynamic rating. The player would need to have three dynamic ratings in the DQ zone in order to be Dynamically DQed. Level of Play DQ Zone 2.5 Level Level Level Level Level Level 5.20 If a player s dynamics reaches the DQ Zone three times (each dynamic that reaches the DQ Zone is called a strike) then the player strikes out of the level and is moved to the next highest level.

4 In 2009 players with ratings (computer C or benchmark B ) will not be subject to Dynamic Disqualification. Players who reach the DQ Zone will have their ratings moved up to the next level of play at the end of the year. Individuals with S = Self-Rate, T = Tournament only, A = C rating borderline appealed down, D = Already DQed up a level, and M = played mixed doubles only ratings will still be subject to the possibility of Dynamic Disqualification. Comparison Chart: For each possible score in a tennis match, there is a numeric figure that represents the difference in games won and games lost by the participants in the match. As an example: if two players compete in a match then the score of the match is equal to this numeric difference in the two player s ratings. Example: 6-4, 6-4 score of a match is approximately equal to a numeric difference in their ratings of.24 in the CompuRank Comparision Chart. So if the winning player had a rating of 3.20 then the opponent should have a rating of 2.96 for the 6-4, 6-4 match. ( = 2.96) In the dynamic rating section listed previously it was mentioned that the comparison chart was used to see if both player s dynamics were in line with the comparison chart. In the above example, if the losing player s current dynamic was not 2.96; then the system would need to adjust both player s dynamic ratings accordingly. Match Rating: A match rating is a single numeric figure based upon one tennis match score. Each time a player competes in a match (against a player with a computer rating) a dynamic rating is calculated. It is calculated by generating a Match Rating from the outcome of the match, and then averaging it into the current dynamic ratings to come up with a new dynamic rating. Once again the Comparison Chart is used to find the numeric rating difference. Each player s current dynamic is then used to create a match rating for each of them. Their match rating is then averaged into their current dynamic with the last three previous dynamic ratings and a new Current Dynamic Rating is then achieved. End of Year Ratings: The end of year ratings are not just the dynamic ratings. For the benchmark players the end of year ratings are their benchmarks that are calculated by using a benchmark-derived rating averaged with their current dynamic rating. Computer rated players who are not benchmarks (did not play at any championships) receive a benchmark-derived rating. Benchmark-Derived Ratings: This is a rating run of the matches played in a certain pool of matches. For example; at the National Championships, all of the matches played at that championships is the pool of matches played. So the process starts at the National Championship for each level of play. The winning team at Nationals is benchmarked using their dynamic ratings and then the matches they played against all of the other teams will generate ratings for those players. This then cascades down to the other teams that played at nationals that did not have direct match play against the winning team. The process runs through about 10 times to smooth out the numbers, and then when it can t smooth anymore it is finished. At any of the championships this process ends with a

5 fusion of the Benchmark-Derived Rating Run and the Final Dynamic ratings for all of the teams that participated at Nationals but did not win Nationals. Match Data Included in the Rating System: Certain data is always included in the rating system such as USTA Adult League, and Senior League match data. The National Office of the USTA allows each section of the USTA to determine if other match data will be included in the rating calculations. Some of the data that the section can exclude or include is NTRP Tournament Match Data, Super Senior Match Data, etc. For the USTA Missouri Valley this exclusion or inclusion can vary from year to year. This explanation was prepared by the district leagues coordinator. Should you have any questions about the material, please contact Steve Hossack at or cell.