Division 3: Weston A v Hutton Moor (Thu 08 Mar 2007)
Match played between Sarah Barber (home) and Jayne Large (away).
Match won by Sarah Barber. Result: 9-3,9-5,9-2.
Starting level for
Sarah Barber:
124, level confidence: 60%.
Starting level for
Jayne Large:
74, level confidence: 60%.
Sarah Barber to win as she is currently playing
68% better than Jayne Large.
Sarah Barber won all of the games and 73% 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 67% (english scoring).
These are weighted and combined to calculate that Sarah Barber played
67% better than Jayne Large in this match.
Assuming that any level changes are shared between both players, for this result it looks like Sarah Barber actually played at a level of
124 and Jayne Large at a level of
74. Without any damping, both players would need to be adjusted by 0% to match this result.
Allowing for the difference in level between the players, the adjustments have been reduced to 0%.
Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Sarah Barber changes to 0% and Jayne Large changes to 0%.
After applying standard match damping, the adjustment for Sarah Barber becomes -0.1% and for Jayne Large becomes 0%.
Apply match/event weighting of 75% for 'Womens Winter 2006-7' so the adjustment for Sarah Barber is 0% and for Jayne Large is 0%.
Increase level confidence due to one more match played. Sarah Barber: 77%, Jayne Large: 78%. Reduce level confidence based on how unexpected the result is. Sarah Barber: 77%, Jayne Large: 78%.
Final level for Sarah Barber:
124, level confidence: 77%.
Final level for Jayne Large:
74, level confidence: 78%.
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!