Once players have been rated, they will begin playing competitions. It will then be necessary, on the basis of matches played, to re-evaluate and re-rate the players on a regular basis. When competitive match results are used to adjust the players ITN rating, a decision will need to be taken regarding the most appropriate calculation formula to be used.

Obviously, countries will have to decide on the method of calculation that best suits the particular conditions in that country. Some countries will choose to use a very simple system while others may choose to use a more sophisticated system. Cost and administrative time will be a major factor in this decision. The ITF has developed, in conjunction with the Taskforce, a simple calculation formula for re-rating players. This system is outlined below:

Type of system: The recommended ITN Calculation Formula ystem is a head-to-head system.

Which matches count towards the ITN?

It is recommended that only matches recognised by the national, regional, provincial association and or club count towards the ITN i.e. so called official matches. These matches can take place in a tournament, in a team-competition or a club-match. Official matches should be played under the ITF Rules of Tennis. So, if players want to have an ITN that is re-evaluated according to their match results, they should participate in competitions using match formats within the ITF Rules of Tennis.

When does the ITN calculation system start?

Players will get their first ITN on the basis of their most recent competitive history or by participating in an ITN On Court Assessment conducted by an authorised person. From then onwards their ITN rating will be decided by results in official competitions or in the case of recreational players ITN 10 to ITN 7 by completing additional ITN On Court Assessments.

Who deals with the results of these matches?

It is recommended that only authorised people be responsible for dealing with the results from official competitions or ITN On Court Assessments. The tournament directors, referees or coaches should collect the results and send them to the relevant governing body (national, regional or provincial association or club) immediately after the completion of the competition or assessment. Official computer or hand-written forms could be created and used for this purpose.

How often should the ITN rating be calculated?

The ITN rating should be calculated at least once a year. However, it is recommended to calculate the rating twice a year or every three months. Obviously, how often the rating is calculated will depend on the number of players participating as well as on the means available.

Is there a minimum number of matches required to get an ITN rating?

It is recommended that the minimum of matches within the period of evaluation should be 6, but fewer matches are possible.

What about defaults and walkovers?

In an effort to avoid players giving walkovers on a regular basis, players winning by walkovers should not be given points for these wins. In addition, if a player gives more than 3 walkovers in a year they should be penalised.

What if a player does not compete?

Players who do not compete at all for more than a year will need to be rerated.

HOW DOES THE CALCULATION FORMULA WORK?

The ITN Calculation can be done manually or run on an excel spreadsheet on a computer. The result of the calculation shows the player’s new ITN rating.

• For a win against a player of his own rating, a player gets + 1 point
• For a win against a player of one rating band higher, a player gets + 2 points
• For a win against a player of two rating categories higher, a player gets + 3 points etc.
• For a loss against a player of his own rating, a player gets - 1 point
• For a loss against a player of one rating band lower, a player gets - 2 points
• For a loss against a player of two rating categories lower, a player gets - 3 points etc.
• For a win against a player one or more rating categories lower or a loss against a player one or more rating categories higher, no points are given because these wins or losses are expected.

Incorporating Doubles Results into The ITN

National Associations wanting to include the results of doubles matches in the ITN, could consider the following:
To calculate points won when playing doubles, add together the ITN’s of the two opponents (Opponent 1 and Opponent 2) and subtract the ITN of the partner (D = B + C- A) - see chart below. The value obtained represents the opponents combined “doubles” ITN and can be treated in the same way as that of a singles opponent. The singles formula can then be used as normal to calculate the points won. This gives the National association the ability to maintain separate spreadsheets for singles and doubles or combine them on the same spreadsheet. The results in doubles will then count towards the singles ITN of each player.