The International Tennis Federation (ITF) World Tennis Number is a new, single global tennis rating for all players, regardless of age, ability or gender. The USTA, along with over 135 other international governing bodies to-date, has adopted the ITF World Tennis Number.
The ITF World Tennis Number does not replace NTRP ratings or USTA rankings.
Below is a collection of questions and answers that provide an overview of the rating system and technical details.
Please choose from the links below for additional information specific to junior or adult players.
What is the ITF World Tennis Number?
The ITF World Tennis Number (WTN) provides a global standard for players. It is a 40-1 scale, with 40 being a beginner player and 1 being an elite professional. This scale is for all players, regardless of age, gender, or ability. Players have separate ITF World Tennis Numbers for singles and doubles.
ITF World Tennis Number was developed by the International Tennis Federation (ITF). The ITF is the international governing body of tennis that works with national associations worldwide to support the growth of the sport.
What is Tennis ID?
Tennis ID is a unique identifier allocated by the International Tennis Federation (ITF) automatically and free of charge to allow a player to be identified in multiple different WTN databases and to have their results connected, creating an accurate global number.
How do I get an ITF World Tennis Number?
Participation in USTA and ITF events will result in a WTN rating. Players need match results in order to generate an initial rating. Initial WTN ratings may be at a lower “Confidence Level” until more match results are recorded. Green ball and Yellow ball results are credited towards a player's WTN as long as all players with a match are at least 9 years old. Players who are 7- and 8-years old who have earned their way from Orange ball into Green ball can also have a rating once they've played a Green ball match.
What are the benefits of the World Tennis Number?
- GameZone — Easily identify players at your level for closer matches, more fun, and more improvement
- Player Development — Statistics to track your progress and help improve your game
- Future Seeding, Selection, and Flighting by WTN in USTA Ranked Tournaments and Level-Based Tournaments
- International system — Players from all over the world will be using the World Tennis Number
- WTN to be used in ITF tournament selection
- A tool for college coaches to evaluate prospective student-athletes worldwide and could be used for selection and seeding in college tennis events
- Track favorite players, friends, professionals, local competition, team comparisons
Why did the USTA partner with ITF on WTN?
To participate in the global standard for all tennis players, regardless of age, gender, or ability. The WTN facilitates more game enjoyment and development by bringing together more players at a given playing level in any given geographic area. This reduces costs and makes tennis more inclusive and accessible.
How will WTN be used in the United States?
Here are a few ways the United States plans to use WTN in the near future:
- Ratings-based events
- Selection and seeding in USTA junior tournaments
- A tool for college coaches to evaluate prospective student-athletes and selection/seeding into college/open tournaments
- ITF junior and pro acceptance
When will USTA start to use the WTN?
In 2022, the USTA will begin a phased rollout of various WTN usage.
Where can I find my WTN and WTNs of other players?
You can access your WTN and WTNs of other players by signing into your account on usta.com and viewing player profiles.
What information is displayed on a player's WTN profile?
A WTN profile includes the player's name, gender, nationality, ITF WTN, and age information. The age information displayed for a player varies as described below:
- For players under 14, the site will display as 'Under 14'
- 14+ to 19 years old, display "Born in YEAR"
- For 20+, ages are shown in the following bandings:
- If the age is 20 to 30, displays as '20 - 30'
- If the age is 31 to 40, displays as '31 - 40'
- If the age is 41 - 50, displays as '41 - 50'
- If the age is over 50, displays as '50+'
Will college coaches use WTN?
WTN will become one of the key tools college coaches may use to assess players worldwide. Most every nation where a college coach is recruiting will be providing their national association results to WTN. The significance of having many nations providing data is that it allows for an apples-to-apples comparison amongst players of various parts of the world. More data = more accuracy.
What cost is associated with WTN?
WTN is free. There are no costs associated with WTN for players or providers.
How is WTN calculated?
The WTN algorithm uses match result data as provided by a player’s national association (USTA) to calculate your WTN. Results provided by the USTA from as far back as 2016 can be used in calculating your rating. The more data used, the more accurate the rating. Pre-match ratings of both players are used by the algorithm to project what it thinks the outcome of your match will be. Your WTN changes depending on your match score and how it compares to the projection. Current results carry more weight than older results. Over time, a result carries less and less weight in your rating calculation. Match results are analyzed at set level; the algorithm takes into account each individual set as its own result.
When are WTNs updated?
The WTN Rating is published each Wednesday at approximately 3:00 am EST.
Why is WTN updated weekly?
WTN is updated weekly due to the vast amount of data and the frequency with which the data is contributed. There are over 135 national associations providing data every day. With this amount of data, a weekly release of updated WTNs is most sensible. From a developmental standpoint, weekly updates are plenty of data points. For these reasons, the ITF feels that weekly is the best interval on which to update WTNs.
What is GameZone?
GameZone is the range of player ratings where you will achieve the most competitive matches. This range will include players with slightly higher and lower WTNs than your own. Gaining match results within your GameZone is the fastest way to improve your WTN.
How is GameZone determined?
GameZone is your range of opponents where either player would have a probability of winning the match of between 35%–65%.
What is the Confidence Level?
The Confidence Level is a measure of how accurate your rating is. A blue checkmark to the right of your WTN indicates a high level of confidence in your rating’s accuracy. A gray checkmark to the right of your WTN indicates a lower level of confidence in your rating’s accuracy. In order to increase your Confidence Level, you’ll need to add more match results to your WTN profile.
How is Confidence Level calculated?
Confidence Level uses many statistics. Prominent metrics include +total matches, how current the matches are, total opponents, and confidence level of opponents.
What is the relationship between the WTN rating and its Confidence Level?
The Confidence Level is derived from a quantity called rating deviation in the Glicko-2 methodology. A player’s rating is a central measure of his/her estimated ability. The rating deviation augments the knowledge of that estimate by providing a measure of uncertainty around that central measure. As the rating deviation decreases, the algorithm becomes more certain on the central estimate. Confidence Level is a transformation of rating deviation.
The Confidence Level can have a significant impact on a player’s rating. Faced with the same set of results, two players with the same rating, but with different Confidence Levels, will experience different rating updates. The player with a lower Confidence Level will see his/her rating fluctuate more.
The factors that make the Confidence Level change are stated in the previous section.
How is my Confidence Level determined?
As a guideline, the Confidence Level of your ITF World Tennis Number will fall if you are inactive for two months. If you compete in 5+ matches in a two-month period, your Confidence Level will remain higher. The more matches you play, the more confident your rating will be. The highest Confidence Level occurs at 30 recorded matches or more a year.
Are weightings applied for levels for types of tournaments?
Currently, all tournaments and competition types have the same weight; the pertinent factor for updating the rating is the opposing player’s rating.
What is the effect of a long time off court?
During time periods in which a player does not compete, his/her rating remains unchanged, but his/her confidence level decreases. This is the way the algorithm captures the increased uncertainty around a player’s rating.
Players who do not take part in competition for a significant period, caused by injury, off-court issues or other factors, will have a lower confidence level when they return to play. The algorithm will react more strongly to the results as it tries to calibrate the player’s rating after a long absence of data.
My WTN is wrong. What can I do?
If you see an incorrect match result on your WTN, please contact the event director to have this reviewed. Your WTN will automatically update the following week if a change was made. If it has been more than two weeks since the completion of an event and you find results are missing, please send an email to email@example.com with these details:
• Player’s Name
• Player’s USTA Number
• A link to the event page
I won my match. Why did my rating go down?
Your match results, despite winning, may not have met or exceeded the algorithm’s projection.
I lost my match. Why did my rating go up?
Your match results, despite losing, may have exceeded the algorithm’s projection.
What match results will count towards my WTN?
Any tournament or league match that is recorded on a USTA platform counts towards your WTN. The result will count toward WTN regardless of whether or not WTN was used to select, seed or flight players.
How can I improve my WTN?
You’ll need to consistently outperform the algorithm’s expected result.
How do defaults affect my rating?
Defaults are not factored into a player’s WTN.
Does a default or retirement impact my WTN?
A default does not count toward a player’s WTN. A retirement where a set has been completed does count toward a player’s WTN.
To learn more about the ITF World Tennis Number, visit https://www.worldtennisnumber.com/eng/faq