Notification of enhancement to the ITF World Tennis Number algorithm calculation

In July 2023, the ITF will be making important improvements to the World Tennis Number calculation, to help ensure that player ratings continue to be as accurate as possible. These enhancements will see a significant proportion of players’ numbers move in either direction.

The ITF World Tennis Number's weekly calculation is now powered by data from 50 nations, sharing 22 million match records from around the world.

The calculation is continuously monitored and tested by the ITF. When necessary, the ITF will responsively and transparently adjust the calculation to ensure it remains accurate. This change will take place on Wednesday 26th July 2023. 

What are the changes?

This enhancement to the WTN algorithm will reposition cohorts of players on the current scale of 1-40 and ensure that players from all over the world are more accurately aligned, particularly with regard to different age groups. While your number is likely to be adjusted, you will see less significant movement within your own age group.

The principles behind the ITF World Tennis Number calculation and the most Frequently Asked Questions about the change are available here.