Explaining level changesDivision 2: Kingsdown v Lansdown Avon County Girls (Thu 05 Nov 2015)Match played between Kathryn Atherton (home) and Lucy George (away). Match won by Kathryn Atherton. Result: 9-3,9-4,9-0. Starting level for Kathryn Atherton: 206, level confidence: 53%. Starting level for Lucy George: 94, level confidence: 23%. Kathryn Atherton to win as she is currently playing 119% better than Lucy George. Kathryn Atherton won all of the games and 79% of the points. This games result would be expected if she was better by around 55% or more. This points result would be expected if she was better by around 97% (english scoring). These are weighted and combined to calculate that Kathryn Atherton played 97% better than Lucy George in this match. Due to the difference between the players' levels, allow for the likelihood that Kathryn Atherton was taking it easy by anything up to 15%. This gives her an allowed level range for this match between 143 and 206 without affecting her level. In this case, Kathryn Atherton played at level 185 and remained within her allowed range so her level will not be adjusted. Consequently, Lucy George is considered to have not played better than expected and her level will also not be adjusted. Increase level confidence due to one more match played. Kathryn Atherton: 73%, Lucy George: 48%. Reduce level confidence based on how unexpected the result is. Kathryn Atherton: 69%, Lucy George: 45%. Final level for Kathryn Atherton: 206, level confidence: 69%. Final level for Lucy George: 94, level confidence: 45%. 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!
|