Division 1: David Lloyd Green v Thornbury (Thu 03 Jul 2008)

Match played between Anne Nugent (home) and Kate Bowen (away).
Match won by Kate Bowen. Result: 7-9,7-9,9-5.

Starting level for Anne Nugent: 163, level confidence: 63%.
Starting level for Kate Bowen: 91, level confidence: 56%.
Anne Nugent to win as she is currently playing 79% better than Kate Bowen.

Kate Bowen won 67% of the games and 50% of the points.
This games result would be expected if she was better by around 20%.
This points result would be expected if she was better by around 0% (english scoring).
These are weighted and combined to calculate that Kate Bowen played 10% better than Anne Nugent in this match.

Assuming that any level changes are shared between both players, for this result it looks like Kate Bowen actually played at a level of 128 and Anne Nugent at a level of 116. Without any damping, both players would need to be adjusted by 40% to match this result.

Allowing for the difference in level between the players, the adjustments have been reduced to 29% and 29% respectively.
As this is a best of 3 match rather than best of 5, these adjustments have been reduced to 21% and 21% respectively.

Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Kate Bowen changes to +21% and Anne Nugent changes to -18%.

After applying standard match damping, the adjustment for Kate Bowen becomes +11.6% and for Anne Nugent becomes -10.4%.

Apply match/event weighting of 65% for 'Womens Summer 2008' so the adjustment for Kate Bowen is +7.5% and for Anne Nugent is -6.5%.

Increase level confidence due to one more match played. Kate Bowen: 75%, Anne Nugent: 79%. Reduce level confidence based on how unexpected the result is. Kate Bowen: 53%, Anne Nugent: 56%.

Final level for Anne Nugent: 153, level confidence: 56%.
Final level for Kate Bowen: 98, level confidence: 53%.

Notes

• This calculation is done in two main parts; first work out the adjustment needed to match the results and then apply damping. This means that levels should always be 'about right' but the time taken to get there or the volatility is dependent on the damping.
• A level also has 'level confidence' which drops if players haven't played for a long time or have had enexpected results. As low confidence levels adjust more quickly than high confidence levels, it allows these players to find their level more quickly without impacting their opponent's level too much.
• Point scores are used as well as game scores for accuracy - particularly important for 3-0 results - though we can work with game scores only too, albeit with more damping.
• Mismatched players are allowed for - you don't have to hammer your opponent. See explanation above if this applies to this match.
• The section on damping is where we still have some options. We have recently made a change to damp league matches more than tournament matches and box matches even more than that. This gives added weight to the more important matches.
• There are occasional, very small adjustments made to all players to keep the averages constant which are not covered here.
• You don't get a bonus just for winning - if you want to go up you have to play better than expected against your opponent.
• We have spent more than 5 years fine tuning the level calculations based on tens of thousands of match results and a great deal of feedback from players, team captains and coaches. It's the most usable and accurate ranking system there is in any sport, let alone squash.
• For a more complete explanation of how levels are calculated (on which this system is based) see the help file here.
• If you have thoughts/opinions on the above or any feedback on the way levels are calculated or updated, please contact us. We welcome all feedback, although we are keen squash players ourselves and would pefer to be on-court than in front of a screen so please be patient and please do try to see if your question has already been answered on the help page. We are unable to answer questions about hard anyone played in their match - we only get to see the results - and if your level didn't increase as expected please make sure you've looked at the above explanation before contacting us. If you want to go up the levels, train harder, listen to your coach and win more points. Or just be incredibly talented!