HOW THE RATINGS WORK
History

The ratings started for the 1998-99 season. Every player registered during that season was given a rating of 100.

The system of devising ratings has been refined a few times over the years (so going back to the stats for season 1999-00 to try and work out your new rating for season 2000-01 may not give the same value as shown in the Ratings Archive).

Put simply, how do they work?

Every player gets a game rating for every Singles game played during matches and Singles Competitions, which includes the Open and Silver Singles and the Veterans KO. It used to also include the Captains and Vice-Captains KOs, but will no longer do so now that the format has changed.

The winner of the game gets their opponents rating +50, the loser gets their opponents rating -50.

You can only get a game rating against rated players, you can never get a rating lower than your own for winning a game, nor can you get a rating higher than your own for losing a game.

In addition, unrated players cannot get a rating greater than 50 for a loss. Estimated ratings for new players are adjusted game-by-game once they have played the minimum five rateable games.

At the end of the season, the game ratings are added up to calculate a new Season Rating for each player, provided the player has played at least five rateable games.

Finally, the Player Rating (also known as the Three Year Rating) used for the next season is the average of the last three Season Ratings (except where indicated below, see ***).

Note: new players playing less than five rateable games will not be given a Season Rating nor a Player Rating.

What's all these "E"s and "U"s about?

Season Ratings may be qualified by the letter "E" or "U".

"E" means that the player played at least five, but less than ten, games from which a game rating could be calculated, so their Season Rating is estimated or "E".

"U" means that a rated player played less than five games from which a game rating could be calculated, so their current Player Rating is used for their Season Rating, but for that season is qualified as being unrated or "U" and their new Player Rating remains unchanged. This is so that a Player Rating can be maintained over a period of time for players who drop in and out of the league.

A Player Rating qualified with an "E" means that the player either does not have the full three seasons used to calculate a Player Rating, or one of their three seasons is in itself qualified with an "E" or "U".

*** One complicating factor: if a player has a "U" rating from the previous season, their new Player Rating will be the same as their rating for last season (it seems illogical for a Player rating to change if the player did not play).

CLEAR AS MUD.

Okay, what about an example of how a Season Rating gets calculated?

Let's look at an example for a new player joining the league, Colin Bloggs:-
#Game Opponent Result Colin's Player Rating Opponents Player Rating Game Rating Comments
1 Ian W n/a 75 125 Colin starts with a win, so for the game gets Ian's rating plus 50
2 John W n/a 106 156 Another win, so the game rating is John's plus 50
3 Gary L n/a 123 50FIX A defeat, and unrated players cannot get a rating more than 50 for a loss
4 Tim L n/a n/a n/a A defeat, but Tim is also a new player, so no rating can be derived for the game
5 Neil L n/a 94 44 A defeat with a game rating of Neil's minus 50
6 Jason W n/a 72 122 Another win, so the game rating is Jason's plus 50.
Now Colin has played five rateable games, so will get a rating of his own from now on
7 Dennis L 99 102 52 A defeat, so it's Dennis's rating minus 50, note not fixed at 50 as Colin now has a rating
8 Jack W 91 33 91cap Colin's rating will change for every game now, as he's a new player with no real Player Rating.
This time he has beaten a player rated so far below him that he would get a rating lower than his own for a win, so the game rating gets fixed at Colin's current rating
9 Alan L 91 n/a n/a This time he has lost to a new unrated player, so no rating can be derived for the game
10 Kevin L 91 155 91cap This time he has lost to a player rated so far above him that he would get a rating higher than his own for a loss, so the game rating gets fixed at Colin's current rating
11 Ray L 91 102 52 Colin finishes the season with a loss

So, Colin's rating for the season is calculated to be (125+156+50+144+122+52+91+91+52)/9 = 87E, "E" because he has played less than ten rateable games.
Colin will now carry this through to next season, where his Player Rating for the entire season will be 87E.

Okay, what about an example of how a Player Rating gets calculated?

Following on from the previous example:-
#Season Player Rating Season Rating New Player Rating Comments
1 n/a 87E 87E No Player Rating to start with, and a Season Rating of 87 calculated at the end of the season, qualified with an "E" because Colin has not played the three seasons required to get a complete Player Rating.
2 87E 105 96E A Player Rating of 87 for the whole season, and a Season Rating of 105 calculated at the end of the season, so the new Player Rating becomes the average of the two, again qualified with an "E" because Colin has not played the three seasons required to get a complete Player Rating.
3 96E 104 98E The new Player Rating is the average of the last three Season Ratings, but still qualified with an "E" because one of Colin's three seasons required to get a complete Player Rating has a qualifying "E".
4 98E 122 110 Now Colin has played four seasons. His new Player Rating is the average of the last three Season Ratings, so his first Season Rating of 87 drops out of the calculation and none of the three Season Ratings have a qualifiying letter ("E" or "U") so the new Player Rating doesn't either.

Last modified 20-Jun-07