SquashLevels is a very dynamic system so the level changes after each match can come as a bit of a surprise at first. This is also what makes the system so engaging as you really do get something out of each match - even if it's a reminder you need to keep putting the effort in!
For a detailed explanation of what the algorithm was 'thinking' you can go to the match review page (click 'review' in the match block) and then click on 'view full explanation'. This re-runs the algorithm in verbose mode and you can see the reasoning behind any level change.
There are a lot of factors involved but if your level changed a lot then it's likely to be one or more of the following:
- You haven't played for a while. This drops our confidence in your level so any changes are less damped as we try to get your level to where it should be now more quickly. We also limit how far your level can change if you play regularly - e.g. 4 matches over one weekend in a tournament.
- Your opponent is a very similar level to you. As the difference between the opponents increases, the result is less reliable (think of the extremes) but if you guys are the same it should be a very close, competitive match. Therefore the result is taken more literally if you are very similar level.
- The result was much more one sided than it should have been. Losing 11-6 means that your opponent played twice as well as you for that game. If that happens for all three games then that's effectively a shock result (if you were more even than that) and so you'll both move quite a bit.
On the plus side... a shock result that caused your level to drop more than you'd expect reduces your level confidence so that increases the potential to regain your level back in your next match so, assuming you're back to your normal self again, you should be able to recover fairly quickly.
Good luck!