Spin Rating 2023

Spin Rating 2023

Spin Rating - What’s your Spin?

The Spin Rating is a number that accurately determines your skill level in tennis and is age and gender neutral - so any two players with a similar rating can have a competitive match!

A player gains points after winning a match and drops points after losing a match so the higher your Spin Rating, the higher your skill level.

This allows players participating in a Spin League to get the closest and most enjoyable matches, as they will be grouped with players of a similar skill level based on their ratings.

And with your very own Spin Rating chart on your profile, you can now track your progress and improve your game!

How is it calculated?

The Spin Rating uses a sophisticated mathematical calculation called Glicko which is similar to rating systems used in chess and video games.

When players compete, it analyses the pre-match rating of both players and the algorithm then predicts what it thinks the outcome of the match will be. A players’ Spin Rating will then change depending on the actual match result and how it compares to the prediction.

The exact number of points won or lost is calculated based on the difference in rating between the players (the bigger the difference, the bigger the amount of points won or lost) and how certain both players ratings are (based on the number of matches played and playing in the league consistently).

It takes into account all the Spin League matches you have played, which means that the more you compete, the more accurate your rating will be.

How often will it update?

Your Spin Rating will get updated every 24 hours allowing you to see the changes the day after submitting your Spin League match results.

What happens with new league players?

New players that have no previous match results recorded, will be able to complete a quick questionnaire to get a provisional Spin Rating.

This provisional rating will adjust quickly based on the first few match results so that if someone has overrated themselves in the questionnaire, their Spin Rating will drop more to compensate and correct itself.

If a new player in the league feels they have been placed in the wrong division they needn't worry because their provisional Spin Rating will correct itself quickly and we will be able to put you in a more closely matched division the following season.

How do I improve my Spin Rating?

Play and win matches - simples! The more Spin League matches you play and the more you win, the higher your rating will go.

Winning your division in the league will also give you an extra boost to your rating and the chance to play higher rated players the following season!

You can view a graph of your Spin Rating for the last 6 months on your profile to help you track your progress and improve your game.

What about the skill levels displayed on a player’s profile?

The skill levels displayed on profiles in the app eg. 'Intermediate' or 'Advanced' are a player’s self assessed skill level and are completely independent of the Spin Rating.

They can often be incorrect as they can be modified by a player at any time - so it is recommended to use a player’s Spin Rating to gauge a player’s skill level accurately.

Will you use the Spin Rating for friendly games?

The Spin Rating is currently only for league matches - we cannot guarantee the skill levels in friendly matches as players self assess their skill levels in those games.

We hope to implement this for friendly games on Spin in the future but for now playing in a Spin League is the only way to guarantee playing with other players of a similar level.

What if my Spin Rating is too low or too high?

The Spin Rating uses a sophisticated mathematical calculation which is based purely on your initial questionnaire, your previous match wins and losses and your previous performance in the league.

For new players, don’t worry it will readjust quickly based on your first few match results, even if you had over or underrated yourself in the initial questionnaire.

And for existing players, unfortunately the maths doesn't lie - we cannot take into account that you were injured or that you ‘think’ you are a better player - match wins and losses against other players in the league are the only thing that counts and this keeps the system transparent and fair for everyone - plus you can also now win your division to get a ratings boost!

The Spin Rating has been proven to give much closer matches because it is based only on results and not people's subjective ratings and so all allocations in the league are now done purely by Spin Rating.

However, with the system analysing thousands of results for thousands of players at the same time it’s always possible that there could be a mistake - if you think there is something wrong please let us know and we’ll do our best to correct it.

What happens if the match is very close?

The ‘closeness’ of a match is not currently taken into account ie. individual games or sets won are not used in the rating calculations - only whether the match was ultimately won or lost.

We may revisit incorporating the ‘closeness’ factor in the future but in our current testing, the improvements in accuracy in doing so were marginal, and only made the rating system more complicated to understand eg. you could win a match and still lose ranking points if the match was close.

How is the Spin Rating used in the leagues?

Division Allocation

Players will be grouped into divisions based on their Spin Rating. This means if 300 players join a season, they will be sorted by their rating and placed accordingly in divisions of 6-7 players. Fair and square, everyone will know their Spin Rating and why they’ve been placed where they are.

Entry Divisions (for new players who have never played a league match before) will continue to exist to ensure that new players whose skill level is still uncertain don’t get mixed too soon with players who have been playing in the league regularly.

All new players will receive a provisional Spin League Rating which will be automatically re-assessed depending on the results once the season ends.

Promotions and relegations

It is not possible to come first eg. in Division 10 and then move up to Division 9 the next season because the number of players changes every season and therefore division numbers are not comparable from one season to the next.

Instead the top two and bottom two players in a division win / lose points from their Spin Rating to put them in a higher / lower division when divisions are allocated the following season.

The promotion and relegation points are calculated at the end of the season just before the start of a new season and you will be able to see these season end calculations on the Spin Rating graph on your profile.

Please note that finishing a season higher than a certain player (and even having beat them) does not guarantee being placed higher than them next season. If a player below you (or who you’ve beaten) has a higher Spin Rating than you at the end of the season, they will be allocated higher next season.

Division Winner and Runner-up

Spin Rating points will be won as follows:

  1. The lowest value between
    1. The difference between the division’s highest Spin Rating and the player’s Spin Rating.
    2. 200 points.
  2. Plus an additional 50 points for the division winner and an additional 25 points for the runner-up.

(The reason the lowest number between a. and b. is chosen is to ensure that in case the highest Spin Rating in the division is too high, the division winners do not get over-rewarded)

The maximum number of points that can be awarded is 250 pts for the winner and 225 pts for the runner-up.

Example:

Division Winner’s Spin Rating: 3330 Highest Spin Rating in the division: 3440 Rating Points: Lowest value between 110 (3440 - 3330) and 200 = 110 pts, plus 50 pts for division winner = 160 points Division Winner’s New Spin Rating: 3330 + 160 = 3490

Last and second to last

Spin Rating points will be lost as follows:

  1. The highest value between these negative values:
    1. The difference between the division’s lowest Spin Rating and the player’s Spin Rating.
    2. 200 pts.
  2. Minus an extra 50 pts for the last player and minus an extra 25 pts for the second to last.

(The reason the highest number between a. and b. is chosen is to ensure that in case the lowest rating in the division is too low, players will not get over-penalised).

The maximum number of rating points that can be deducted is 250 pts for the last position and 225 pts for the second to last.

Example:

Last position’s Spin Rating: 2516 Lowest Spin Rating in the division: 2340 Rating Points: Highest value between -176 (2340 - 2516) and -200 pts = -176 pts, minus 50 pts for last place = -226 points Last position’s New Spin Rating: 2516 - 226 = 2290

Remaining players

For the rest of the players in a division (those who didn’t finish in the top two or bottom two), no points will be added or removed from their Spin Rating.

Point Limit

Please note that the maximum amount of points that can be won / lost from your Spin Rating is 250, so even if a player wins 100 points consecutively for 3 seasons, they will only get 250 extra rating points in total - this will be displayed on the rating graph as Point limit Reached.

This is to ensure that winning leagues gives a rating boost to play higher rated people but not at the expense of on overly inflated rating that would result in a skill mismatch.

Skipping seasons

Players that skip a season will lose 25 rating points for every season they skip up to a maximum of 50 points. This is to reward players that play regularly and ensure that returning players are not placed higher than the last time they played.

Unfortunately, while there may be a genuine reason for skipping a season eg. due to injury, this penalty is automatically applied and there can be no manual exceptions.

Walkovers / Retirements

Walkovers do not affect the Spin Rating but a retirement does as that effectively counts as a match loss.

Why don’t you use WTN (World Tennis Number)?

Conversations with the governing bodies, about any kind of collaboration have been very slow and so we decided that the best way for us to continue innovating and improving the leagues was to roll out our own Spin Rating.

WTN and the Spin Rating both use a Glicko based algorithm to rate players but the big advantage of creating our own rating system is that we can customise it and give players on Spin a much better league experience than anywhere else.

Changes to the Spin Rating - July 2023

The following changes will be made for all league seasons going forward:

  • NEW: The Spin Rating (skill level) and Competition points (performance in a season) used in previous seasons will now be combined into a single Spin Rating to easily track your skill level going forward.
  • NEW: You will now be able to see a graph of your Spin Rating on your profile for the last 6 months, so you can see how winning / losing matches and winning / losing your division can affect your rating (Spin Ratings & graphs will update every 24 hours).
  • The exact amount of points won or lost for finishing in the top two or bottom two of a division varies and is dependent on the Spin Rating of the other players in that division up to a maximum win / loss of 250 points - they will now remain a part of a player’s rating and not be reset after one season as happened in previous seasons.
  • This maximum is also cumulative so the total number of rating points that can be won / lost from your Spin Rating is 250 - so even if a player wins 100 pts consecutively for 3 seasons, they will only win 250 extra rating points in total - this will be shown on the rating graph as Point limit Reached.

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