The International Tennis Federation (ITF) is introducing a series of improvements to the World Tennis Number (WTN) to support the long-term sustainability of the system and ensure even greater accuracy for the growing global player community. These improvements will be introduced the week of August 10, 2026 and are based on feedback from players, coaches, providers and national associations.
Below is a collection of questions and answers that provide an overview of the enhancements.
How Does The WTN Rating System Work?
Game-Level Scoring ("Every Game Counts")
Three-Year Rating Window & Activity
Match Completion & Retirements
How Does The WTN Rating System Work?
- Every player has a WTN before each match
- Based on both players’ ratings, an expected outcome is calculated
- After the match, ratings are adjusted based on the difference between the expected and actual result
- If you perform better than expected, your WTN will improve and and if you perform worse than expected, your WTN will decrease
- Most importantly, playing and competing is what matters most - ratings simply reflect how you perform
What’s Changing?
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A greater focus on recent performance
- WTN will now use a rolling three-year rating window. This ensures ratings better reflect current level while keeping the system efficient as global participation continues to grow.
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Every game will count
- The algorithm will now consider the score within each set. For example, a close 6–4 set could result in a smaller rating movement than a one-sided 6–0 set when a match is played within the Game zONe.
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Better reflection of player development
- Ratings will better reflect natural player development over time - particularly for juniors - helping improve alignment with adult levels.
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More accurate ratings for inactive players
- For players who have not competed for over a year, ratings may gradually adjust to reflect the absence of recent competitive results.
These improvements will help ensure that the WTN continues to:
- Reflect match performance
- Encourage resilience and competitive effort
- Support player development
- Continue to encourage fair and meaningful competition
General Questions
Why is the World Tennis Number (WTN) algorithm changing?
The enhancements improve how ratings reflect match performance and respond to feedback from players, coaches, providers and National Associations. The changes are designed to make ratings fairer, more reflective of current playing level, and better aligned with player development.
Will my rating change because of these updates?
Algorithm enhancements could affect all players, as the ITF are making fundamental changes to how ratings are calculated. The ITF’s analysis indicates that players who compete regularly are generally less affected in terms of their position relative to other players but their rating may see an improvement.
Overall, will most players see their ratings go up or down?
The primary outcome is improved rating accuracy, with ratings better reflecting current performance, player development and relative position among peers.
Will these changes affect tournaments and events that use WTN?
Tournaments will continue to operate as normal and if they use WTN, they will do so based on the information available prior to the entry deadline. The primary change is that ratings should provide a more accurate reflection of current playing level and competitive performance.
Will the WTN algorithm change again in the future?
Yes. WTN will continue to evolve as participation grows globally and feedback is received from players, coaches, National Associations and providers.
How is the doubles algorithm affected?
The doubles algorithm will also have the same set of changes applied to it. In addition, the doubles algorithm will also stop considering the rating of your partner in the calculation to better reflect your performance against your peers.
Game-Level Scoring ("Every Game Counts")
What does "every game counts" mean?
The rating calculation now considers the game score within each set, rather than only the set result. This means that closer sets, such as 6-4 or 7-5, are treated differently from more one-sided sets such as 6-0, providing a more accurate reflection of match performance following feedback from players and coaches.
I won my match but my WTN didn't improve. How is that possible?
WTN reflects not just whether you win, but how you perform compared to expectations. If you are expected to win comfortably but the match is closer than the algorithm’s expectation, your rating may stay the same or get worse. This helps ensure ratings accurately reflect performance levels.
Is there a benefit to winning by a larger score?
Generally, more decisive wins can result in greater positive impact, especially when they exceed expectations. However, the system is designed to recognize overall performance.
Is there a limit to how much a big win can improve my rating?
Rating changes continue to consider the rating of your opponent as a key part in your performance. For example, a dominant win against a stronger opponent is likely to have a greater impact than a dominant win against a weaker opponent.
Do different match formats affect ratings differently?
All recognized match formats are included in the WTN calculation. The system adjusts for different formats to ensure ratings remain fair and consistent.
How are tiebreaks treated in the rating?
Tiebreaks are included as part of the overall match result. However, they are not treated in the same way as a full set because they are played over a shorter format.
Three-Year Rating Window & Activity
What is the three-year rating window?
The algorithm now focuses primarily on match results from the past three years, helping ensure ratings reflect recent performance and current playing level.
Will older match results disappear?
Older results will continue to appear in a player's match history. However, once they fall outside the three-year rating window, they will no longer influence rating calculations.
Will my rating drop suddenly when older matches fall outside the three-year window?
No. The transition is gradual. Older matches naturally reduce in influence over time, so rating changes are typically smooth rather than sudden.
Can playing more matches remove older results faster?
No. The three-year window is based on time, not match volume. Playing more matches will not accelerate the removal of older results, but it will provide more recent results that help inform your current rating better.
What happens if I don't play many matches?
Ratings are most accurate when based on recent activity. If you play less frequently, your rating becomes less reliable and your confidence level may decrease over time.
Inactivity & Rating Decay
Why are ratings adjusted for inactive players?
If a player has not competed for a long period of time, their rating may no longer reflect their current level. Gradual adjustments help maintain fair competition and improve the accuracy of ratings.
Will my rating decrease if I stop playing for a while?
If you do not compete for over a year, a small and gradual adjustment may be applied to reflect the impact of inactivity.
What happens if I return to tennis after a long break?
Your rating may have adjusted slightly during your period of inactivity, but it will quickly become more representative of your current level once you resume competing regularly.
Player Development
Will younger players see changes to their ratings over time?
Yes. The system includes a small adjustment to reflect natural player development, particularly among junior players. This helps ensure ratings remain aligned with improving physical and technical ability.
Game zONe
What happens if I play someone outside my Game zONe?
Matches against players both inside and outside your Game zONe count toward your rating. However, matches within your Game zONe generally have greater relevance because they represent more competitive matchups.
Will playing opponents far above or below my level harm my rating?
Not necessarily. The system considers the expected outcome of the match. Playing stronger or weaker opponents will not negatively impact your rating if your performance aligns with expectations.
Match Completion & Retirements
What happens if a match is not completed, for example due to retirement?
The algorithm considers available score data while maintaining fairness and integrity within the rating calculation.
Is there any advantage to stopping a match early to protect my rating?
No. The system is designed to discourage this behavior. Completing matches and competing for every game provides the most accurate reflection of performance.