## Explaining the UK Rankings

The UK Rankings have evolved over the years and since January 2015 we have used a ratings system. On this page, we hope to guide you through this system and how it works. The ratings system prioritises your match results over your final finishing position at an event, as it focusses on each match you play in a tournament. As a result, every match counts and your final match in a tournament may be more crucial than your first! For each match played, the winner gains a number of rating points and the defeated player loses the same number of points.

The amount by which the ratings go up and down is determined by the difference in rating points between the two players at the start of the match. The higher rated player would be expected to win the match, and the greater the difference between the players ratings at the start of the match, the more likely the the higher rated player is to win. The number of points change in each rating is based on the difference between the players. When the higher rated player wins, the larger the gap in ratings, the smaller the points gain/loss between the players.

*Examples *

**Midlands Open 2015, Men's B event - Quarter-finals: James Pope (14893) Vs. Julian Clapp (15755)**

Julian Clapp won the match (21-18, 21-16, 8-21, 21-12) and gained 3 ratings point, as Julian was rated nearly 1000 points higher than James at the start of the match.

**Hertfordshire Open 2014, Men's O45s Event (Round Robin) - Jon Schofield (15635) Vs. John Davies (15534)**

Jon Schofield won the match (21-14, 21-4, 16-21, 8-21) and gained 186 points, as Jon S and John D were closely rated at the start of the match, the win was not as expected and therefore the victor (Jon S) gains more points for it,.

When the lower rated player wins, they gain points and the higher rated player loses points. The larger the ratings difference before the start of the match, the more points the lower rated player gains and the higher rated player loses. Even a smaller ratings gap can result in a big ratings gain for the lower rated player.

*Examples*

**Midlands Open 2015, Men's B event Paul Mathieson (15326) Vs. Julian Clapp (15578).**

Paul Mathieson won the match (15-21, 21-7, 23-25, 16-19) and gained 220 rating points (maximum change is 250 points per match).

**Swedish Open 2016 - Men's C event Jon Spinks (14872) vs Jonathan Wan (14874)**

Jon Spinks won the match (21-2, 8-21, 11-21, 21-17 - Spinks on a gumi-arm) and gained 122 rating points (despite a starting ratings gap of just 2 points!).

These examples highlight how each match affects your rating, and the UK Rankings are determined by the value of your rating score, the higher your score, the better your UK Ranking. Within this system we have a number of technical details such as the rating classes and individual sports ratings. These elements are additions to the system, and are explained below. However, the above text outlines how the system is applied to all Racketlon matches, whether played in the UK or elsewhere on the FIR World Tour.

## Technical Details of the UK Racketlon Ratings

In this section, we outline the various technical details of the UK Racketlon ratings system.

## Rating classes

There are 4 National Classes and 1 International Class within ERA ratings. The national classes are A, B, C and D, and the international class is "+". The range of each class is 2000 pts. Each national class is divided into 4 sub-classes, ie A is divided into A1, A2, A3, A4, where A1 is the highest sub-class in A. International class is split into 5 classes 0+, 1+, 2+, 3+, 4+ in descending order. Class D4 starts at 10,000 points.

These rating classes are applied to both the overall rating and the individual sport ratings. For UK Tour events, it is expected that players with an A1 to A3 rating would play in the A events, with A4 players maybe playing in the B events in stronger tournaments. Similarly, B1 to B3 players would play in the B events, but in stronger tournaments they may drop down to the C events. If players are playing on FIR World Tour events, it would be expected that you would downgrade yourself 2 sub-classes and then re-assess which category you eneter. For example a B3 player in the UK would probably drop to the C event on the World Tour,

## Individual sports ratings

Each player has an overall rating and a rating for each individual sport. The individual sport ratings are the methodology used to generate a new players intitial rating (see next section). We maintain the individual sport ratings for all players (you can view yours on your player profile) and they change as each match is played (you may be able to see this in your personal graphs). Unlike the overal ratings (which are only affected by the match result, won or lost), the individual sport ratings respond to the size of the win.

- If a match is close in an individual sport, say 21-18, then ratings don't change much.
- If a match is a relatively comfortable victory in an individual sport 21-13, then there the number of rating points won or lost is higher.
- If a match is very one sided in an individual sport, say 21-6, then there is a much greater difference in the number of points won or lost.
- As long as at least 11 points have been played in tennis, the tennis is scaled up to the equivalent of the leading player having 21 points. For example, if the match is stopped at 7-5, the overall score for changing ratings is scaled up to 21-15.

It is important to remember that your individual sport ratings are irrelevent to your overal rating and therefore your UK Ranking, but we hope you enjoy seeing your personal sport ratings as an indicator of your progress (or lack of) in each sport. It could also be a sneaky way to check out your future opponent, for example anyone playing James Pope (rated B1 overall, with sports rated as B3, B1, A4, C1) might well expect a harder time in the middle sports than in either TT or Tennis (information correct as of 10/06/2016)

## New Player Ratings

A new player gets a new rating by playing against another player who has a rating. A provisional rating is created as follows:

- For each sport, the provisional rating is calculated relative to their opponents rating.
- If their opponent has an A4 TT rating and the new player beats them 21-15, then the new player’s provisional TT rating will be set around 120 points higher than their opponent's. If they lose 21-15, their provisional rating with be set around 120 points lower.
- If a new player plays only one rated opponent in a tournament, then (assuming that they play all 4 sports), they would have provisional ratings for all 4 individual sports. Their provisional overall rating is then calculated as the average of the provisional individual sport ratings.
- If a new player plays more than one rated opponent, then their provisional individual sport ratings for TT is are set at the average of the provisional ratings calculated against each opponent, and are set similarly for the other sports. As before the overall provisional rating is set as the average of the individual sport ratings.

Following a tournament, there is an initial set of calculations to determine provisional ratings for all new players. Then there is a second set of calculations which moves everyone's ratings up or down depending on the result of all their individual matches.

If there is one player who already has a rating playing in a draw, then all the other players can be given provisional ratings through a snowballing technique. For example in an eight player draw with only one rated player that player would play 3 others, who would all be given a provisional rating. The provisional ratings for those 3 players are then used to create further provisional ratings for all the other players that they have played in the draw. And so on.

If there is a tournament draw with no rated players, then none of the players will get rated.

### Equations

The change in rating points after a match, \(\delta\), is governed by the following equation:

$$ \delta = \max(600D \left(1-\frac{1}{1 + e^{0.01(R_L-R_W)}}\right), 250) $$

where \(R_L\) is the rating of the loser before the match was played, \(R_W\) is the rating of the winner before the match was played and

$$ D = \frac{1}{2} + \frac{R_W}{48000} $$

The Dampening Factor (\(D\) in the equation), so that slightly more points are exchanged in a match between Class A players than between Class B players. The reason for this is that when the standard of players is greater there tends to be more consistency in the overall match score.