The official scoring model presently used across all levels of squash, for both amateurs and professionals, is called PARS which means Point A Rally System, in which players are awarded a point for every rally that the win.
A rally is a series of consecutive shots played between players during a game, starting with one player serving the ball and another returning, alternating strikes and returns of the ball between them, across any of the playable surfaces on the court's four walls, until one of the players either hits the ball out of play, out of court or fails to strike or return the ball before its second bounce, at which point the rally ends.
At this point the winner of the rally, the last person to serve or return a good ball, is awarded a point. Every time a rally is played one of the players will win a point.
A game in squash typically consist of multiple consecutive rallies played until one of the players reaches 11 points (PAR 11), at which point that player wins the game.
During a game, when one of the players reaches 10 points (PAR 10), and needs only 1 more point to win the game, "game ball" is called meaning that the next point that that player secures wins them the game.
The only time this changes is if both players secure PAR 10 at the same time within a game.
Since games in squash need to be won by two clear points, when both players reach 10 points, the game needs to continue until one of the players secures two points more than their opponent, for example 10 - 12, 14 - 16, 11 - 13, etc. at which point the player that is two points ahead, after PAR 10, will be awarded the game.
Squash matches are typically played as best out of 5 games, where the first person to win 3 games wins the match, and the remaining two games no longer need to be played.
Similarly to game ball, when a player is playing the match winning game and requires only one more point to win that game "match ball" will be called.
Winning the Serve & Hand outs
Who serves is initially decided by The Spin at the beginning of a squash game. Thereafter the person that wins the rally being played is also awarded the right to serve and is given the opportunity to choose which court back quarter, left or right, they'd like to serve from.
When a player looses a rally i.e. the ball goes out of court, out of play or bounces more than once before that player strikes and returns it, that rally and the following serve is then awarded to the opposing player and a "hand out" is called.
A hand out simply signals a change of player serving, and indicates that the new serving player may choose which court back quarter they'd like to serve from.
Serving after winning a rally
When you're the serving player and you win the rally being played the next serve you take must be from the opposite court back quarter that you served from last. This change of court back quarter continues for every consecutive rally you win.
So if after winning the right to serve, you choose to serve from the left court back quarter and you then win that rally, you must then serve from the right court back quarter. If you then win that rally too you then return to serve from the left and so on and so on, until your opponent wins a rally and with that the right to serve, causing a hand out aka a change of server to be called, at which point they can decide what side they'd prefer to serve from.
Who serves when & from where
- If you were the serving player at the beginning of a rally and you win that rally you continue having the right to serve, however your next serve must be taken from the opposite court back quarter that you last served in.
- If you were the serving player at the beginning of a rally and you loose that rally a "hand out" is called signalling a change of server and that serve is now awarded to your opponent as the the rally winner. After each hand out the serving player may choose which court back quarter they'd like to serve from.
In summary whoever wins the rally wins the right to serve. If you were the server at the beginning of that rally you must change the court back quarter you serve from. If you weren't the server of the rally but have just won the right to serve, effecting a hand out, you get to choose which court back quarter you want to serve from.