Some people wishing to become referees, many players and even some novice referees have experienced confusion when faced with certain phrases or terms used in Snooker.
One of the most common instances is the difference between a ball-on and an object ball. The explanation is however simple and easily understood.
The balls used for Snooker comprise of one cue ball and 21 object balls. The meanings of the terms are quite clear in that the cue ball is the only one that may be struck with the cue and then only with the tip. Besides this being tacitly understood it is also stated unambiguously in the rules that using an object ball as the cue ball is a foul and is subject to a penalty of 7 points.
The 15 red and 6 coloured balls are named as object balls because it is the objective of the game to score the points each one has as a value when they are potted.
The term ‘ball-on’ differs from the term ‘object ball’ only by the fact that it is a ball which may be used to score points at any given time during a frame, or struck first to avoid fouling. In other words, a ball which may be propelled into a pocket or struck first without the referee calling ‘foul’. A ball-on does not have to be struck first to be a scoring ball, as long as the ball that enters a pocket is a ball-on it will be a fair scoring stroke, including the proviso that it or another ball-on was struck first. So, it should become obvious which is which once the phrase is married to the action.
Cue ball – To be struck by the cue.
Object ball – Used for the game’s objective, i.e. to score points.
Ball-on – Object balls that can legally be struck first and/or potted.
Keep in mind too that only way to score points in Snooker is with these balls, as any points gained from an opponent because of fouls are points that have been awarded not points scored. With that being the case, the objective always remains and the balls so named never cease to be object balls.
So, a ball-on is always an object ball. An object ball is always any ball except the white whether it may be potted or struck first or not.
Regardless of whether the striker will score points or foul by first striking any ball or causing it to be potted or pocketed they are still all object balls if they are not white.
Just as an object ball cannot be used as the cue ball so the cue ball cannot be an object ball. It can never be either a ball-on or a ball-not on, as it will always be a foul if it is pocketed and it can never be snookered with the intention of gaining penalty points. A large percentage of those fouls that accrue a penalty of 7 points involve the cue-ball because it has no assigned value and that is because it has no scoring objective in the game.
This visual representation may help to ease any confusion.
The definition ‘is, or could be a ball-on’ is used for the colours 15 times each during a frame which is not conceded, forfeited or awarded. If the final sequence is added then the definition ’ball-on’ becomes valid 16 times for each. Each red is a ball-on as many times during a frame where a player starts a turn or has potted one of the colours.
It is very different in Billiards as a cue ball in this game can be an object ball and this is because there are effectively two cue balls. The ball assigned at the start of a game of Billiards to the player who is the striker, is the cue ball, with the ball assigned to the non-striker and the red ball being object balls. The phrase ‘ball-on’ is also not used in Billiards as both the balls that are object balls at any time may be used in scoring strokes, or struck first without fouling, except in certain circumstances involving Baulk which does not concern the meanings of these phrases, so as such they are both always balls-on and do not require the phrase.
One further small point to make regarding phrases is that the two, potted and pocketed, are distinct from each other in that the former is legal and will result in a score and the latter is not and will result in penalty points being awarded to an opponent.