Premier A: Lansdown 1 v Redland B (Wed 04 Mar 2009)
Match played between Tim Jones (home) and Danny Webster (away).
Match won by Danny Webster. Result: 9-4,9-4,7-9,5-9,0-9.
Starting level for
Tim Jones:
2,623, level confidence: 65%.
Starting level for
Danny Webster:
3,104, level confidence: 51%.
Danny Webster to win as he is currently playing
18% better than Tim Jones.
Danny Webster won 60% of the games and 54% of the points.
This
games result would be expected if he was better by around 10%.
This
points result would be expected if he was better by around 9% (english scoring).
These are weighted and combined to calculate that Danny Webster played
10% better than Tim Jones in this match.
As Danny Webster has played below his allowed range at 2,961, his level reduction is 2.9% before damping. On the assumption that Danny Webster would normally have been playing at level 3,078 (based on typical behaviour), Tim Jones played better than expected and therefore gains a pre-damping level increase of 3.4%.
Factoring in the relative levels of confidence which allows players with low confidence in their levels to change more quickly, the adjustment for Danny Webster changes to -2.6% and Tim Jones changes to +2.4%.
After applying standard match damping, the adjustment for Danny Webster becomes -1.8% and for Tim Jones becomes +1.7%.
Apply match/event weighting of 75% for 'Mixed Spring 2008/2009' so the adjustment for Danny Webster is -1.3% and for Tim Jones is +1.3%.
Increase level confidence due to one more match played. Danny Webster: 71%, Tim Jones: 81%. Reduce level confidence based on how unexpected the result is. Danny Webster: 69%, Tim Jones: 78%.
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 Tim Jones:
2,653, level confidence: 78%.
Final level for Danny Webster:
3,060, level confidence: 69%.
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!