The Science Behind ITF World Tennis Number

The Science Behind ITF World Tennis Number (WTN)

Having a well-matched partner or opponent is a big part of having the best tennis experience possible. No matter where you are in the world, and no matter what your skill level, the WTN enables you to find players of a similar standard. Whether you are looking for a good challenge, a routine win, or something unpredictable, WTN makes it easy to find precisely the kind of play you are seeking! We want more people playing the sport we love and playing more often... Game. Set. Matched.

What does my WTN mean?

WTN is a scale from 40 (beginner) to 1 (elite professional). This unique scale enables us to offer ratings to the full range of tennis players around the world. New and beginner players will receive an ITF WTN closer to 40, whereas world class professional players are closer to 1. Depending on where you are in the world, you might also see your rating include a decimal place or two. These decimals provide even greater precision for tracking your progress and finding events and ideal match ups! 

How’s it calculated?

The WTN algorithm uses all the match result data shared with the ITF from a player’s history since 2016 to calculate an WTN. When a player or partnership compete, the algorithm analyses pre-match ratings for all the players on the court.

From there, the algorithm predicts an expected outcome for the match based on the relative ratings of each player. Player ratings change based on the difference between expected scores and actual match outcomes. The more match results the system holds, the more accurate a player’s rating becomes. Once a player has several matches in a given period of time and based on the opponents they play, a player’s rating could become “verified” with a blue tick indicating that the system has enough information to highlight that the player’s rating is reliable.

WTN analyses matches at set level, meaning it takes each set as its own result. Simply, if a match ends 2 sets to 1 in your favour, then the system will update your rating with two set ‘wins’ and one set ‘loss’.

Even if you don’t win the overall match, the sets you have won will be considered accordingly in the WTN calculation.

What match results will count towards the WTN?

Any completed match results supplied by participating Tennis Associations will be included in the WTN. Retired match results can also count towards your rating depending on how many sets are played.

Does it help me to play people with a weaker WTN?

Playing opponents of various levels impacts your WTN based on how well you play. If playing an opponent a significantly weaker rating and coming out with a strong win, it is likely that your WTN will not change as you performed consistent with the prediction.

How will my WTN improve?

WTN is here to inspire and support your tennis goals, whatever they might be. If your aim is to improve your game and therefore your rating, it couldn’t be simpler. All you need to do is keep playing and performing better than our algorithm predicts you will.

How often will my WTN update?

The WTN is updated weekly and where players do improve, the average rate of improvement is 0.27. How much your rating changes week to week will depend on how much you are playing. If you want to see your WTN improve, be sure to stay active on the court.