ITF World Tennis Number
TENNIS NZ INTRODUCES ITF WORLD TENNIS NUMBER (WTN)
Since the launch of WTN in New Zealand early this year the WTN player ratings have been updated based on results from tournaments and teams events, but excluded interclub results. However there is also much competitive Interclub tennis so we have been searching for a way to include these results in WTN. Good news is that some Interclub results will now feed into the WTN calculations.
- Which results – all interclub results where both players already have a WTN rating. For doubles matches all 4 players need a WTN.
- When – interclub results will be uploaded monthly starting with September’s results.
- Who has a WTN now – about 8000 members who have played in a tournament in the last 5 years.
- What about players who don’t have a WTN - If an Interclub only player wants a WTN then they will need to register on a Tennis NZ website which will link their Match Hub Member Id to the ITF. This will enable their interclub results to be included. More info on this process will be available shortly.
The inclusion of interclub results should both improve the WTN accuracy, especially of adults who mainly play interclub, and also encourage good juniors to continue playing in interclub competitions.
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In April 2023 Tennis NZ introduced the ITF World Tennis Number (WTN) – a brand new, inclusive and modern rating system for all players.
The ITF together with the LTA, the USTA and other leading tennis nations have cooperated in the development of the new player rating system, which will be used by national associations around the world to help create a common language across tennis.
It is a single global tennis rating for all players, regardless of age or ability or gender - from the world’s elite to a player taking part in their first competition.
WHY DID TENNIS NZ ADOPT THE WTN?
The modernisation and innovation of NZ's grading system was identified as a priority area to improve on during Tennis NZ's Competition review by coaches, referees, players, and parents. The ITF WTN presents an excellent opportunity to meet this goal and for New Zealand based players to be part of the world’s largest tennis rating system.
Furthermore, the WTN is not just for performance players and in future it will be the foundation of any social tennis format where matching players on ability is a key contributor to success.
HOW THE WTN WORKS
Players are assigned a WTN number between 40 and 1. Beginners start at 40 and professionals are nearer to 1.
The ITF used 4 years of NZ tournament results up to November 2022 to calculate the initial WTN number for each player. A weekly process adjusts the WTN numbers based on new tournament results. Players have separate WTN numbers for singles and doubles.
The WTN also provides a Confidence level for each player. Those who are playing frequently will have a high confidence level, meaning the confidence in the accuracy of their WTN number is high. Confidence levels are an important feature of WTN as they impact the significance of a win or loss and influence the speed with which player ratings can change. View the FAQ section at the bottom of this page for further details.
Currently, the WTN database for New Zealand contains 10,200 tournament players.
The timeline for the rollout of the WTN in New Zealand
The roll out will begin in early April with Tennis NZ and Regions using the WTN for seeding in the upcoming National and Tier 2/3 events for the remainder of the 2023 season. From April onwards the WTN should be the main scale for seeding players in national, regional, and association run events. As the WTN becomes more widely known and talked about, we will see a transition of all association and club run tournaments using the WTN.
A roll out of the WTN to interclub only players is dependent on the replacement of Match Hub.
What this means for Match Hub
Tennis NZ will continue to run the Match Hub competition system for the current 2023 summer season for interclub and leagues. All players will still have a Match Hub grading - for both singles and doubles. This is necessary for organising divisions in many interclub competitions.
As the WTN is rolled out, players will see their WTN number in your player profile on the Tennis NZ tournament website.
View an example player profile
The first goal is to replace the Tennis NZ Match Hub grading with the ITF WTN for acceptance criteria and seeding for sanctioned tournaments.
WTN and Match Hub are similar in concept in that all matches count towards a player's rating. However, a significant difference is that the WTN considers the 'closeness' of a match. This means that a player can benefit from a close loss in a match that they are expected to lose anyway. In Match Hub a 3-set loss is treated the same as a straight sets loss.
The second goal is to replace Match Hub for interclub and box leagues with a system that will also integrate with the WTN. Once this occurs, those players who are solely interclub players would be assigned WTN numbers.
FAQS
If you have a question about the World Tennis Number that is not currently in the FAQs below, please email info@tennis.kiwi and we will look into adding it to the list.
- Belong to a tennis club affiliated with Tennis NZ: Find a Club
- Be registered in our Match Hub system. Ask your club to do this.
- Play in a Tennis NZ sanctioned tournament: Upcoming Tournaments
Your initial WTN rating is assigned at the next WTN Update and is calculated using a method that looks at the ratings of the other players in the tournament (of the same gender, age group, and with a high Confidence Level) and then this is further refined by comparing with the initial values of players in the same age group.
Initial WTN ratings are set at a lower “Confidence Level” until more match results are recorded.
The WTN is a dynamic system that updates every Thursday pm.
The weekly Update includes all results from tournaments that completed on or before the previous Saturday. Therefore tournaments that end on a Sunday do not get processed until the following week.
e.g.
tournament ending Saturday June 10th will be processed on Thursday 15th.
tournament ending Sunday June 11th will be processed on Thursday 22nd.
For every match the WTN algorithm analyses each players' pre-match rating and predicts a winner. Each player’s WTN Number will then change based on the score and how it compares to the prediction.
The more matches a person plays, the more effective the algorithm becomes, meaning players can feel confident that their Number is accurate.
Four years of match history were used to calculate the initial WTN numbers.
Yes, match results are analysed at set level, meaning the algorithm takes into account each individual set as its own result. The WTN algorithm compares its score prediction with the actual score to determine what a player’s specific rating should be.
A retirement where a set has been completed does count toward a player’s WTN.
The ITF World Tennis Number range is from 40 (lowest) to 1 (highest).
A complete beginner will receive a Number near to 40, which they can gradually start to improve as they play. At the other end of the scale, pro players will be closer to 1.
Depending on where you are in the world, a player’s Number might also include a decimal place. This provides even more precision when selecting a potential opponent.
The Confidence Level is a measure of how accurate your rating is.
A Confidence Level of 70% and above indicates that the WTN is verified. There will be a tick beside the rating on the player profile.
Initial WTN ratings are at a lower “Confidence Level” until more match results are recorded.
The more matches you play, the more confident your rating will be.
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.
As a guide, a verified WTN (70% and above) can be achieved by completing 5 or more matches in a consecutive 5 week period. There are instances where slightly more matches are required, such as if a player has had an extended time away from playing.
With the move to World Tennis Number, players over the age of 9 will have their WTN displaying on their player profile: https://tnz.tournamentsoftware.com
Unfortunately, there is not a WTN view for the general public just yet.
The ITF are working on a function where it is available to the general public, as the data / statistics shown in the back end are great.
At the moment, this view is only for the national sporting bodies.
In General
- A single global scale for everyone, regardless of age, gender or ability
- A Number for singles and a Number for doubles
- Find opponents that are evenly matched to you, wherever you are in the world
- Be part of the largest global tennis community
- A modern online system that will calculate a player’s Number on a weekly basis
- A searchable online community of players
- Statistics to track and improve your game as well as analyse opponents, including win/loss ratios and head-to-head comparisons
- Free to use
2023 NZ Tournament Play
- Will encourage players into tournament play to improve their ratings.
- The WTN accentuates the positive match play outcomes over the negatives.
- The WTN will be used as an additional entry acceptance criterion for ITF tournaments
Casual Play
- A personalised Game zONe to help identify opponents of a similar skill level to yours
- Compare performance on a global scale whilst finding localised level play
- Ability to build a favourites list of players at your school, club or among friends
- The WTN can match you with players of a similar standard and can also be used to find a suitable doubles partner.
Tournament results indicate that Match Hub and WTN are closely aligned for seeded players. Generally, the same players would be seeded but not always in the same order.
However it is important to consider the WTN confidence level when making comparisons. Ratings of players with a WTN confidence level of less than 70% need to be checked as they may not align directly to their Match Hub grading. Similarly players in Match Hub who have not played for a couple of years will often have an inflated grading.
During time periods in which a player does not compete, their rating remains unchanged, but their 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.
No. ITF World Tennis Number is for everyone - a single global scale for all players, regardless of age, gender or ability.
The ITF World Tennis number is a global system and as such any player who has competed abroad in a nation that also supports the ITF World Tennis Number will have one number which reflects all matches played at home and abroad.
It’s a tool for college coaches to use to evaluate prospective student-athletes worldwide. Along with many of the world’s National Tennis Federations, of note the Intercollegiate Tennis Association in the USA, responsible for the administration of college tennis, have just announced the World Tennis Number as their official rating.
This will have flow-on effects for NZ players either currently involved in the college system or seeking college scholarships and highlights the importance of aligning with the global system that the World Tennis Number provides. More info on this partnership here.
The ITF's official WTN website will only display players who are playing junior ITF events.
The display of a WTN for any other NZ junior player is through the Tennis NZ tournament website: https://tnz.tournamentsoftware.com/find/player
The roll out will begin with Tennis NZ and Regions using the WTN for the upcoming National, and Tier 2/3 Events for the remainder of the 2023 season onwards.
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