The ITF World Tennis Number uses match result data from 2016 to calculate a player’s number. When players compete, it analyses the pre-match rating of both players. The sophisticated mathematical calculation then predicts what it thinks the outcome of the match will be. Players’ Numbers will change depending on the actual match score and how it compares to the prediction. 

The more results the system holds, the better the calculation will understand a player’s ability, and therefore, its “confidence” in the Number.

Match results are analysed at set level, meaning we take into account each individual set as its own result. 

Example

If a match ends two sets to one, then the system will update the winning player’s Number with two set ‘wins’ and one set ‘loss’. Even if a player doesn’t win the match, any sets they have won will count towards their Number.

Unlike the previous LTA Rating, there are no set timeframes in which to record any match results with the calculations using up to four years’ worth of match data to initialise a player’s Number.

This means that in order for a player to improve their Number they simply need to record a better match result than the calculation has predicted.