World Tennis Number Algorithm Enhancements 2026

World Tennis Number (WTN) continues to evolve to provide a more accurate, fair and meaningful rating system for tennis players worldwide.

Based on feedback from players, coaches and national associations, enhancements were made to the algorithm on Wednesday 12th August to improve rating accuracy, reflect real match performance, and support player development at all levels of the game.

A more efficient and sustainable rating system

As global participation in WTN grows, the algorithm will now operate using a rolling three-year rating window.

This means:

• Ratings are based on recent match results
• Older results gradually drop out of the calculation
• The system remains efficient and scalable worldwide

This ensures ratings stay current and accurately reflect a player’s playing level.

Every game now counts

The updated algorithm now includes the use of game-level scores, rather than only set-level results.

Previously, a 6-0 set and a 6-4 set had the same impact on ratings. Now:

• A 6-0 set produces a larger rating movement
• A 6-4 or 7-5 set produces a smaller movement
• Close matches are more accurately reflected

Rating changes are also influenced by the expected outcome of a match, meaning performance is measured against what the algorithm predicts.

This encourages players to compete for every game and rewards strong performances - even in close losses.

Supporting player development

To better reflect how players can change physically in terms of strength and power, especially juniors, a player development adjustment has been introduced.

Ratings may be gently adjusted based on:

• Age
• Time since last match
• Typical development patterns

This helps ensure ratings reflect a player’s likely current level, particularly during key development stages.

Ratings reflect current playing level

A rating decay mechanism has been introduced to account for players returning after time away from competition.

• Ratings gradually adjust after extended inactivity
• Changes are controlled and incremental
• Ratings remain relevant to current performance

This helps returning players compete at appropriate levels and improves fairness across the system.

Continuing to improve WTN

These enhancements ensure the WTN system continues to:

• Reflect real match performance
• Encourage competitive effort and resilience
• Support player development
• Create fair and meaningful competition

WTN will continue to evolve based on feedback from the global tennis community.