Squash isn't an Olympic sport (yet!) but it has an interesting scoring system. In the traditional scoring system you can only score points when you are serving, but if the score reaches 8-all the player who is not serving can decide whether to play to 9 points or 10. This activity is a starting point for mathematical investigation, and is designed to be accessible to students of GCSE maths (Key Stage 4).
There is a very clear explanation of the traditional scoring system on the BBC website at http://news.bbc.co.uk/sport1/hi/other_sports/squash/4748522.stm.