Division 2: Workout Harbourside A v Chippenham Olympiad A (Thu 10 Feb 2022)
Match played between Alana Robertson (home) and Jenny Plummer (away).
Match won by Alana Robertson. Result: 15-6,15-7,15-7.
Starting level for
Alana Robertson:
474, level confidence: 73%. Set manually.
Starting level for
Jenny Plummer:
284, level confidence: 62%.
Alana Robertson to win as she is currently playing
67% better than Jenny Plummer.
Alana Robertson won all of the games and 69% 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 125% (PAR scoring).
These are weighted and combined to calculate that Alana Robertson played
125% better than Jenny Plummer in this match.
Assuming that any level changes are shared between both players, for this result it looks like Alana Robertson actually played at a level of
550 and Jenny Plummer at a level of
245. Without any damping, both players would need to be adjusted by 16% to match this result.
Allowing for the difference in level between the players, the adjustments have been reduced to 12% and 12% respectively.
Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Alana Robertson changes to +10.3% and Jenny Plummer changes to -12%.
After applying standard match damping, the adjustment for Alana Robertson becomes +6.6% and for Jenny Plummer becomes -7.6%.
Apply match/event weighting of 75% for 'Womens Ladies Spring 2021/2022' so the adjustment for Alana Robertson is +4.9% and for Jenny Plummer is -5.6%.
Increase level confidence due to one more match played. Alana Robertson: 86%, Jenny Plummer: 79%. Reduce level confidence based on how unexpected the result is. Alana Robertson: 74%, Jenny Plummer: 68%.
A final adjustment of +0.1% has been made to both players as part of the automatic calibration that is performed after each match. All players in this pool will have been adjusted equally in order to remain equivalent to other player pools.
Final level for Alana Robertson:
494, level confidence: 74%.
Final level for Jenny Plummer:
271, level confidence: 68%.
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!