About the SquashLevels System
SquashLevels is the ranking system for all squash players.
It collects results from a large number of league, tournament and box systems and calculates the level each player is playing at for every match. It covers all abilities from complete beginner right up to the very top players in the world. Once you know your level you'll always be able to answer that fateful question - how good are you? You'll know which box to play in, which team to play for, wherever you choose to play.
You can find combined player histories, level charts and stats for all players on the system. You can even enter your own results. If you play squash you should be on here - you probably already are!
It's the next big thing in Squash.
What's different about SquashLevels?
There are a few ranking systems around but SquashLevels is unique for a number of reasons:
There are very few ranking systems that do any of these, let alone all of them. SquashLevels is the most comprehensive ranking system available.
A player's level is a number that represents how good they are. For example, if a player has a level of 2000 then they are twice as likely to win a rally against an opponent with a level of 1000 - on average. In this case, for every 3 rallies, the 2000 level player will typically win 2 and the 1000 level player will win 1, on average. Same applies for 4000 versus 2000. There's no analysis into how good they are at drops, lengths or if they've got a bad knee - just that they will win twice as many rallies.
Note this is based on rallies rather than points which is where the English scoring system complicates things a bit but, don't worry, SquashLevels can spot English scoring and take account of it.
How good is good?
Levels are calculated as a relative measure between players but with the large number of players we have in the system and the spread between complete beginners and the best in the world we do actually know enough to make sweeping statements about how good a player is based on their absolute level.
Level history examples
With a player's results on the system and levels adjusted after each match, they get a level history which is shown as a chart. Here are two examples:
Comparing with tournament based rankings
The SquashLevels system generates ordered lists of players based on their level so it is similar to the rankings but it is also different.
The official rankings use a points system that is based on how far you progress through a tournament; the further you progress the more points you get, the more prestigious the tournament, the more points are available. These points are averaged over the last 12 months and managed by the appropriate bodies such as the PSA whereas SquashLevels are based on recent results and provide a number (i.e. level) for how well someone is playing 'at the moment'.
In both cases, the top players are at the top but player levels show how well someone is playing at the moment. They are a good indicator of what the rankings will show in the future.
SquashLevels will give you a level as long as you have a result whereas you have to get through at least the qualifiers of a professional tournament to get a ranking. As a result, the top of the rankings are very accurate but the lower down you go it becomes less so as you have a mixture of players who only play some tournaments or who never make it past the first round.
You will not have a ranking at all unless you enter one of these tournaments which excludes 95% of the people who play. SquashLevels is fully inclusive.
Rankings are focused on specific categories and not mixed so it's not possible to compare men with women, juniors with seniors or across any of the age categories. With player levels, everyone is measured against the same scale so can be compared. It's interesting to see Nicol David's level for instance - where would she stand in the men's rankings?
Ranking lists tend to be quite short once you stop looking internationally. In the UK there are not that many ranking events for seniors so there isn't really a ranking for England players. Although SquashLevels is not averaged over 12 months it can be used see who all the England players are and what order are they in at the moment (or other time which you can select).
You can use your squash level to know how good you are and predict results
Comparing with the Matrix system
The matrix system is similar to the player levels system but it uses a points value rather than a level. As with the levels system, your points value goes up if you do better than expected and it goes down if you do worse.
The main differences are:
Although the exact points changes between the matrix system and the levels algorithm are a little different, it is still possible to create a mapping from level to matrix to give a good idea where a player might be listed in a matrix system and this mapping is shown in the SquashLevels system for interest and comparison.
Comparing with the Tencap system
The Tencap system has been in use for a while in tennis (hence the name) and provides a similar sort of player ability assessment but calculated in terms of a handicap - so the better players have lower numbers. Here are the Tencap division definitions from the Squash Skills website:
Both the player level and Tencap are based on absolute ranges so it is possible to map from one to the other and we can show the equivalent Tencap for each player on the SquashLevels system. Based on the above definitions:
The Squash Skills Tencap assignments are done based on specific events and tournaments so will only cover a subset of players but it's always good to have a numeric assessment and by mapping from levels to Tencap it allows all players to know which Tencap division they are in.
How it works
When two players play a match they both have a starting level and dividing one by the other gives you the expected result ratio. For instance, a level 1200 player playing a level 1000 player gives an expected result ratio of 1.2.
The actual result is used to generate the actual result ratio and this is based on a combination of the games scores (e.g. 3-1) and the points scores (e.g. 9-4, 9-7, 6-9, 9-5 - which adds up to 33-25). This isn't a straight forward conversion mathematically because of the complexities of the English scoring system but we overcame that by simulating ten million games of squash from varying starting ratios and then generating a table we could use to look up.
This allows us to take the games result (3-1) and match result (33-25) and work back to a result ratio very quickly and then compare with the expected ratio which is what we started with.
The basic algorithm is very simple at that point because the player who does better than expected is adjusted up and the player who does worse is adjusted down. However, we have to take a number of factors into account which cause us to reduce the amount of adjustment each time:
Here's the graph for the points ratio and games ratio for english scoring.
You can see a few interesting things just looking at the graph:
Note, despite the smooth looking line on the chart, there are only a small set of real games ratios, especially if we only focus on the winner:
For combining the points and games ratios we use other guidelines derived from the same emulation (not shown here):
With 3-0 wins, the points ratio becomes a bigger factor as the score gets closer to 27-0.
Calibration of levels
The player level algorithm has been in use for quite a few years now and, with the allowances for the many conditions listed above, we have a system that is remarkably accurate. We have compared the top 100 in the world with the official rankings and they are not that dissimilar despite the rankings being averaged over a much longer period. It is certainly true that the better players are at the top and, in fact, quite often, the level system turns out to be a good predictor for what will happen in the official rankings because of the delays between the two.
There are other indicators that help calibrate the system:
Setting initial levels
There are a few different ways that the first level of player can be set:
Where do the results come from?
Any system can connect to SquashLevels allowing results to be retrieved or sent across automatically. We just need to work with the developer of that system to agree the access method and format of the data and we're ready to go. For the systems connected so far, it has taken typically a couple of hours for the developer to add the functionality. It really is that simple!
Currently, results are received automatically from
For every registered system, results are retrieved or received every night at around 4am and then the levels recalculated. Note that all matches are recalculated from the beginning to allow for old matches being entered later on.
Note that during initial set-up, all the results from a system can be transfered across so even if you connect for the first time in the middle of a season, we can pull every available result in (i.e. back to when the local league system was first used) and go from there. You should have access to your entire recorded match history. The only essential requirement is that the source system provides a unique ID for each player. Duplicate IDs we can deal with but having more than one player share the same ID is a problem (though we can deal with that too if need be).
Players who are registered can also enter their own results on-line directly into the SquashLevels system. Note that if a player enters a number of matches and then at some point in the future their local system is automated so that the same matches are now sent across automatically, the SquashLevels system will detect this and only unique matches will be recorded.
Which matches can be included?
Only truly competitive match results can go in to the system which covers
Match results that have been entered manually and are significantly unexpected are detected by the system and reported to the administrator
Which players can be included?
The whole point of the player level algorithm and the SquashLevels system is include all players from beginner all the way up to the top professional. It applies the level algorithm consistently across all age groups and for men and women.
How long is it before my level is accurate?
The system assigns an accurate level from the very first match provided that
A player's first level has low confidence which allows it to adjust faster than their opponent with high confidence. This speeds up the process of getting an accurate level without having too much impact on their opponents.
After a few matches, the system can tell if the initial level was accurate and, if not, it will automatically update that initial level to a more appropriate value. This allows the player's full history to be accurate once the first few results are in and the player is calibrated.
When a player first registers they are able to set their own starting level, based on guidelines, if their first opponent doesn't have one. This level will still be overridden by the system at some point if it proved to be inaccurate.
So, to answer the question, most players using the system correctly will have an accurate level within one or two matches whereas those who start in the wrong place may take anything up to 10 matches to be re-adjusted back to reality.
Are all match results considered equal?
The simple answer is 'no'. For instance, a box game is not as important as a league match and a league match is not as important as a tournament final but we can't arbitrarily increase a player's level just because they're playing in a tournament. So what we do is give a higher weigthing (i.e. less damping) for the more important matches and a lower weigthing (i.e. more damping) for the less important matches.
Specific events or match types can have their weighting set independently by the admins but in most cases; events and tournament matches have full (100%) weighting, league matches have 75% weighting and box matches have 50% weighting. Note that this is in addition to the damping that is already applied to all match results.
This still ensures that a player's level is accurately represented on the system but it's more focused on recent results for, say, a tournament. This means that if you list the players at the end of a tournament then their levels will reflect how they played at the tournament rather than how they got on in the box match before the tournament.
What information can I get from the SquashLevels website?
The system calculates and holds levels for all players after every match allowing you to find out:
With so many players and results on the system it's important that individuals, clubs and counties can have it set up so that it's focused on them and their needs. This can always be done using the player listing filters and then manually setting up preferred default views but we also provide county focused starting points.
It's just a matter of adding the user_mode parameter to the player listing web page which tells the system to set it's defaults for that county. They can be overridden at any time - it's just a starting point which is stored in a cookie.
The league system can then link to SquashLevels using this parameter so that it's users see the county view they want by default. If need be, we can agree specific county defaults.
Here are some examples:
Getting your results in to SquashLevels
There are three ways to get your results in:
If you play in the professional tournaments your results will already be being transferred across.
What if I can't remember the points scores?
Entering the points scores for a result gives the system the best chance for an accurate assessment of level but if you only have game scores it will still work. The extremes are limited so ratios higher than 1.5:1 will have limited effect. Close matches (3-1, 3-2) aren't affected so much by not having the points scores though the level adjustments are still reduced slightly.
Can I enter results via my phone?
We don't currently offer an app for entering results or viewing player level information as, given the amount of information shown on a page, it's really all best viewed on a 'normal' sized screen. 7" or larger tablets with their standard web browsers are fine - it's just the very small phone screens that limit their use. It can be done though...
Controlling what you see in the player lists
As SquashLevels holds the results for thousands of players from many counties and even countries, there is a set of filters at the top of the player listings that allows you to select the players you're interested in.
With these filters you can select the following and then click on 'Show' to show the new filtered list:
Once you have selected the filters you are interested in, you can set that to be your default view by clicking on the word default in the line below the filters.
Note that only players with sufficient level confidence are shown by default as players with rogue levels can disrupt the player lists. These players can be found if you search for them by name.
Registration takes four quick and easy steps:
During the three month trial period you will have full access to all the pages, features, personal results entry and information in the system, after which, you can either pay the registration fee (£5 for the year) to continue with the same level of access or return to basic access. If you choose to remain a basic member, the system will still remember your details and allow you to become a full member at any time in the future.
It's not a huge amount of money - we're just trying to cover costs.
Why should I register?
Once you are registered you will be able to enter your own results and have access to all the information on the website. You will be able to:
Are there different levels of registration?
No. Registration is extremely cheap so there's no point in dividing it into different levels of functionality.
If you are registered then you have access to everything, if you are not, you are limited to the basic view - though that is still quite a lot. You will always be able to find out your level, or the level of any other player without registering as long as the results are on the system.
Counties and clubs can also choose to register all their players so they have full access but that is not common as, although it's a small amount per player, it still adds up for a whole county.
How do I find out about changes/updates?
The SquashLevels system is actively maintained and features are being added all the time. The goal is to provide such a rich set of features that everyone will want to register so do keep checking back for updates which will be posted on the SquashLevels Facebook page if you 'like' us on Facebook you will get the latest updates. We also post updates under About->News.
If you have suggestions do please get in touch.
What should I do if my level appears wrong?
Please report any levels that appear wrong - whether yours or someone else's. This does happen from time to time if results are entered incorrectly or perhaps a game has continued with one player being injured. One rogue result can affect the results of others for a while so it is important to identify them and exclude them from the calculations.
Although the system is quite good at spotting unexpected results, there's nothing like local knowledge of how good players really are to identify inaccuracies.
Anything that's wrong in the system can be corrected, bypassed or removed if need be so it's just a matter of reporting back to us and maybe working with us to understand what's gone wrong.
It's through doing this over several years that has allowed us to fine tune the many cases we now allow for. There may be others yet to uncover as the system scales up. Your help is much appreciated!
My name is spelt wrong. How do I fix that?
If you are registered, you can correct any of your own details from name to age group and even starting level. If you are not registered then please report anything that needs changing back to the system admin.
I'm injured. What will happen to my level?
If you continue to play and your results are recorded and transferred into the SquashLevels system then it is likely that your level will drop to represent how well you are playing while injured. It's not a good idea to play while injured anyway and a drop in level is probably the least of your worries...
When you are fit and back to your previous standard, your level will return fairly quickly - Usually around 2-3 matches. The confidence in your level will drop (both through time not playing and also from the unexpected result of your last match) and that will allow for a faster return to normal afterwards.
If a specific match result should be excluded because, say, the injury occurred in the first game but the results were entered as if the match had continued (e.g. 9-6, 9-0, 9-0) as can happen in league systems, then that result can be excluded from the nightly level processing. Please let us know if this is the case. Don't just do this because you had a bad result! We can spot the difference between that and a genuine match stoppage.
What's to stop people abusing the website?
The levels algorithm is dependent on the accurate recording of truly competitive matches. Incorrect results have a negative impact on the levels of their opponents which then ripples through the system so it is important that only accurate results for truly competitive matches are entered.
Most results come from official and automated sources - they are 100% trustworthy but results entered by individuals could potentially cause trouble so they are checked for unusual results which are then flagged to the administrator. These are then queried back with the person that entered them (we have their email address) and the results excluded from the level calculations at which point they can be corrected or removed.
It is very rare for players of county standard and above to not already be covered by the official tournaments, all of which are already on the system so entering a level too high or having suspiciously good results against top players is easy to spot and highlighted by the system.
Players abusing the system will be removed.
What if I play for more than one county or club?
It's possible that players can be entered more than once in the system if their results come from more than one source. The system is usually able to recognise this because it can identify multiple players of the same name with the same level but the merging of these players is still done manually in case they really are different people.
This manual merging is done by the system admin but usually only after it has been confirmed that the two entries are for the same player. It's hard to separate an incorrectly merged player.
Once the system is told that these 'two' player names are the same player then it will treat all results for either player as one. I.e. once the names are merged, the system will continue to merge the results going forward automatically.
A player from two sources doesn't always have the same name - it is remarkably common to find different abbreviations for instance Jonathan Smith and Jon Smith could be the same player but, then again, maybe not. This is where we need the support of local players to help confirm duplicates.
Is the player level algorithm open source?
No, it isn't. Though a good deal of it is explained on this page and it can be reverse engineered from the level calculation breakdown from player results it is copyright. See the copyright notice at the bottom of this page.
If you want to make use of the player levels algorithm them please just register and make use of the SquashLevels system itself. It's not expensive.
Note that the algorithm is only half of what you need - you also need all the results. It's a bit like a phone system - the more people who have phones, the more useful the system!