With the current rules preventing the spread of coronavirus, many of our regular tennis activities like the winter competition and tennis clubnights such as the Internal Winter Competition are either cancelled or postponed. In order to provide you with a format to play tennis, we have created this ladder. This will be tennis singles where everyone will be ranked based on their performance in tennis matches planned by themselves.

Below you will find an explanation on how the ELO-rating system and challenging works.


When signing up, you indicate your single-tennisrating which determines who you can play against. Once you have signed up, you will receive an ELO-rating of 1500 and a status.

What is an ELO-rating?
ELO-rating is a numerical indication of the strength of a participant. The higher a participant’s ELO-rating, the better they are. Therefore, if you beat a strong player (a high ELO-rating) you will get more points for your win than if you would have beat a weaker player.

How is ELO calculated after a match?
The new ELO will be calculated using two formulas. The first formula calculates your chance of winning. Your chance of winning is calculated by dividing your ELO by the sum of the ELO of both players. For example: if player 1 has an ELO of 500 and player 2 an ELO of 1500, the chances of winning for player 1 and 2 are 25% and 75% respectively.

The other formula determines your new rating. This formula takes your current ELO and adds your progression or regression. This is K*(W-WK). Here, W indicates whether you have won or lost a match (1=win, 0=loss) and WK your chance of winning. K is a variable that is dependent on your current ELO-rating:
ELO of 1200-1800: K = 100
1000-1200 and 1800-2000: K = 75
Less than 1000 and greater than 2000: K=50
If you have a very low rating and you win, or if you have a high rating and you lose, K will always be 100.

If player 1 were to win in the previous example, the new ELO-ratings are:
Player 1: 500 + (100 * (1 - 0.25)) = 575
Player 2: 1500 + (100 * (0 - 0.75)) = 1425

If player 2 were to win, the new ELO-ratings are:
Player 1: 500 + (50 * (0 - 0.25)) = 487
Player 2: 1500 + (100 * (1 - 0.75)) = 1525


Challenging someone

To challenge someone, the following conditions must be complied with:

  • You can only challenge someone who has a better or equal single-tennisrating. Meaning that someone who is a 7 in single can only challenge 7’s, 6’s, 5’s, etc. This is to create a fair and level playing field for the challenged player.
  • You and your opponent should have the right status:
    • You should have the status ‘Active’
    • Your opponent should have the status ‘Active’ or ‘Passive’
    Below you can find more information on statuses

What’s next?

Once you have challenged someone, your opponent will receive an email. Once the challenge is sent, the status of both you and your opponent will be changed to ‘Busy’. Because we assume that everyone checks their email at least once every two days, you have 48 hours to accept or decline a challenge. Hereafter, there are three possibilities:

Your challenge is accepted:
If your opponent accepts your challenge, you will receive an email with the name and email address of your opponent. Now you have 1 week to play the match, the match will be removed and both your statuses will be “Passive”. Once you have played the match, one of you can input the result on the website. The ELO-ratings will be recalculated and your status will be “Just finished”.

Your challenge is declined:
If your opponent declines your challenge, you will also receive an email. The following will then happen:

  • Your own status will be “Active”. Your opponent’s status will be “Passive” for a week.
There is no reaction after 48 hours:
If there is no reaction after 48 hours, this will have the same effect as declining the challenge.

Tennis rules

You play 1 match with a maximum of 3 sets (best of 3). The third set is a normal set.


Active This participant can challenge and be challenged.
Busy This participant currently has a challenge open and cannot challenge or be challenged.
Passive This participant declined a challenge last week, meaning they can only be challenged. If the participant declines again, they automatically lose the match.
Just finished / Cooldown This participant just finished and can challenge or be challenged again after 24 hours. This is to prevent a participant from being challenged 4x on the same day. If you are finished and ready to play again, you can click on “Make me active!” to immediately update your status to “Active”.