The ultimate aim of SquashLevels is to assess the level at which every player on the system is playing after every match they play and give them a number - their level - to represent that.

The level is mathematically comparative between players such that if you are playing twice as well as your opponent then you will have twice the level and this applies all the way from a beginner's first competitive matches to the top pros. This should apply wherever you are, however good you are, whoever you played and whenever you played!

This allows us to plot graphs, compare players, predict results, set goals and even compare players from different eras! Although it's all comparative, it's fixed to a specific level at a specific time so it can actually be treated as an absolute figure. That's really important so that when a player knows what level they are, they know what that means. These are the sorts of levels we find. Numbers very approximate as clubs, counties etc. vary considerably!

• Beginners - (< 100)
• Leisure players (50 - 300)
• Club boxes players (200 - 2000)
• County league players (500 - 3000)
• Top county league players (3000 - 10,000)
• PSL (10,000 - 30,000)
• Satellite PSA (20,000 - 40,000)
• Top PSA (30,000+)

With the vageries of human behaviour, millions of matches over decades of time, it's a complex task!

Levels are calculated for every player after every match and are based on:

• The player's level before the match.
• Their opponent's level before the match.
• The actual result compared to the expected result. Given we know the player's levels before the match we can predict the result if both players played as expected. If the actual result shows that one of the players played better than expected, their level will go up a bit and their opponent's level will go down a bit.
• Maths - to determine how much their levels should change if there was no damping or behavioural modelling. PAR is easy (11-5 is about twice as good), English scoring less so. We use a combination of points scores and games scores to assess the result. The overall goal is that if you are twice as good as your opponent then your level will be double theirs. This works all the up from beginner (<50) to top pro (>50,000)
• Weighting - the more important the match (e.g. a tournament) the greater the weighting. This allows you to play a box match without having too much impact on your league standings.
• Damping - there is a reasonable amount of damping dialled into each match trying to get the balance right between wild swings and slow progress. The algorithm does its best to reward every player for a good result and, in consequence, an appropriate level reduction if the result isn't so good. The intention is that a player's level is a reasonable assessment of their current playing level within a match or two.
• Behavioural modelling - as it turns out, not everyone puts 100% effort in every match and that’s down to behaviour. There are many other cases too where player behaviour defies the maths and, based on the analysis of 1.6 million results on the system, we’ve built an extensive behavioural model that allows us to predict and make use of these behaviours. See the calibration FAQ for more detail on what behaviours we model.

We can work with game scores only, making assumptions around the average 3-0 result (based on our analysis of real 3-0 match results) but we can only use averages so it takes a lot more results for the levels to become accurate. Not all 3-0 results are the same, obviously.

They're really very different but if you order players by their level you will get a ranking and you can compare that with the latest tournament based rankings and usually see the two lists looking a bit the same but not the same. This can cause confusion and lead to the question; 'Why do we have two different rankings?!' It's a fair question!

Level based rankings - which is what SquashLevels generates - are based on a player's current playing level and (as per the section above) that's entirely based on their actual results against their actual opponents. It doesn't matter who the opponent is (it's just their level that counts) or what tournament it is and not which round they are playing in.

Tournament based rankings are based on points accumulated from progressing through the rounds of tournaments over a number of tournaments. Each round is worth more points (usually double) and the whole event is usually scaled so that the more prestigious events (with the better players) are worth a lot more points. Usually, the rankings are based on a points based algorithm such as the average of your best 10 tournaments over the last 12 months. In this case progression through tournaments is everything - in fact not progressing is often worth nothing!

It's interesting to compare the two methods:

• The points gained at tournaments are exponentially geared to the players that win and progress through the rounds. The winners of the tournaments end up with large numbers of points, whereas those that get knocked out early get very little - or nothing. So when the points are added up over a number of tournaments it's very clear who the winners are as they have masses of points. This is a very good method for finding out who the very best players are - and so will always remain the official ranking method for the top players.
• A lot of squash players don't even play tournaments. Or, if they do, it's the odd tournament run at their club once a year. If you need to play in 10 or more tournaments in a 12 month period and progress through at least one round to score any ranking points then that immediately reserves the tournament based rankings for the best players - just the top few in any pool. It's not inclusive. What you typically find is that the tournament based rankings are spot on for the top few players and then go a bit random after that. Those next few players are the ones able to/prepared to travel around and put the time and effort in. Fair play to them but that doesn't necessarily make them better players than those who don't.
• Also, as SquashLevel's levels are based on current performance and it takes a little while for the best players to emerge at the top of the tournament rankings (because they are averaged over 12 months), the levels based rankings are a bit of a look into the future and more likely what the tournament rankings will look like in about 6 months. Very interesting...

So in summary:

• Tournament based rankings are focused on the top few, averaged over a long period of time.
• Level based rankings are inclusive, current, dynamic and a predictor of future tournament rankings.