Snooker rules

Snooker is played on a rectangular snooker table, typically 6 feet by 12 feet (1.8 m x 3.6 m), with six pockets, one at each corner and one in the middle of each long side, though pubs and homes often have smaller versions (two-thirds or one-half scale). At one end of the table (the "baulk end") is the so-called "baulk line", which is 29 inches (74 cm ) from the baulk cushion (the short cushion at the baulk end). A semicircle of radius 11½ inches (29.5 cm), called "the D", is drawn behind this line, centred on the middle of the line. The cushion on the other side of the table is known as the "top cushion".

Because of the large size of regulation snooker tables, smaller tables are common in domestic situations and other situations where space is limited. These are often around 6 feet (1.8 m)in length, and all the dimensions and markings are scaled down accordingly. The balls used are sometimes also scaled down, and/or reduced in number (in the case of the reds) such that the longest row of balls in the rack is omitted.

The balls

Snooker balls, like the balls for all cue sports, are typically made of phenolic resin, but are smaller than pool balls. Regulation snooker balls (which are specified in metric units) are nominally 52.5 mm (approximately 2-fraction|1|15 inches) in diameter [http://www.worldsnooker.com/equipment.htm World Snooker Association, Rules: Equipment] ] , though many sets are actually manufactured at 52.4 mm (about 2-fraction|1|16 in.) Some recreational sets (which are usually not measured metrically) are 2-fraction|1|8 in. (about 54 mm) up to as large as pool balls, at 2-fraction|1|4 in. (about 57.2 mm); larger ball size requires wider pocket openings. Miniature sets also exist, for half-size home tables. There are fifteen Cuegloss|Red ball|red balls, six Cuegloss|Colour ball|"colour" balls (yellow, green, brown, blue, pink, and black), and one white Cuegloss|Cue ball|cue ball. Usually none of the balls are numbered, though the six colour balls often are in the US, where they are easily mistaken at first glance for pool balls (the design is similar, but the numbering does not match pool's scheme).

At the beginning of a frame, the balls are set up in the arrangement shown in the illustration. The six "colours" (a term referring to all balls but the white and the reds) are placed on their own spots. On the baulk line, looking up the table from the baulk end, the green ball is located where the "D" meets the line on the left, the brown ball in the middle of the line, and the yellow ball where the "D" meets the line on the right. This order is often remembered using the mnemonic "God Bless You", the first letter of each word being the first letter of the three colours. At the exact centre of the table sits the blue ball. Further up the table is the pink ball, which sits midway between the blue spot and the top cushion, followed by the red balls, arranged in a tightly-packed triangle behind the pink (the apex must be as close as possible to the pink ball without touching it). Finally, the black ball is placed on a spot 32.5 cm (12.75 in.) from the top cushion.

Objective

The objective of the game of snooker is to strike the white "cue ball" with a cue in the direction of other "object balls" and to pot these object balls in one of the six pockets. This must be done according to the rules of the game, which are described below. By potting object balls points can be scored. The player who scores most points wins the frame, and the player who wins most frames wins the match.

A snooker match

A snooker match usually consists of an odd fixed number of frames. A frame begins with setting up the balls as described above. A frame ends when all balls are potted, or when one of the players concedes defeat because he is too far behind in score to equal or beat the score of the other player.

A match ends when one of the players has won the majority of the set number of frames and the other player can therefore not equal this. For example, when a match consists of 19 frames, the match ends when one of the players has reached 10 frames.

Gameplay

At the beginning of each frame the balls are set up by the referee as explained. This will be followed by a "break-off shot", on which the players take turns. At the break-off, the white cue ball can be placed anywhere inside the D, although it is common for players to start by placing the ball on the line, between the brown ball and either the green or yellow ball.

Players take turns in visiting the table. When one player is at the table, the other cannot play. A "break" is the number of points scored by a player in one single visit to the table. A player's turn and break end when he fails to pot a ball, when he does something against the rules of the game, which is called a "foul", or when a frame has ended.

The ball or balls that can be hit first by the white are called the ball(s) "on" for that particular stroke. The ball(s) "on" differ from shot to shot: a red ball, if potted, must be followed by a colour, and so on until a break ends; if a red is not potted, any red ball remains the ball "on". Only a ball or balls "on" may be potted legally by a player. If a ball not "on" is potted, this is a foul.

The game of snooker generally consists of two phases. The first phase is the situation in which there are still red balls on the table. In the first phase, at the beginning of a player's turn, the balls "on" are all remaining red balls. The player must therefore attempt to first hit and pot one or more red balls. For every red ball potted, the player will receive 1 point. When a red has been potted, it will stay off the table and the player can continue his break. If no red has been potted or a foul has been made, the other player will come into play.

In case one or more red balls have been potted, the player can continue his break. This time one of the six colours (yellow, green, brown, blue, pink and black) is the ball "on". Only one of these can be the ball "on" and the rules of the game state that a player must nominate his desired colour to the referee, although it is often clear which ball the striker is playing and it is not necessary to nominate.

When the nominated colour is potted, the player will be awarded the correct number of points (yellow, 2; green, 3; brown, 4; blue, 5; pink, 6; black, 7). The colour is then taken out of the pocket by the referee and placed on its original spot. If that spot is covered by another ball, the ball is placed on the highest available spot. If there is no available spot, it is placed as close to its own spot as possible in a direct line between that spot and the top cushion, without touching another ball. If there is no room this side of the spot, it will be placed as close to the spot as possible in a straight line towards the bottom cushion, without touching another ball.

Because only one of the colours is the ball "on", it is a foul to first hit multiple colours at the same time, or pot more than one colour (unless a free ball has been awarded (q.v.)

If a player fails to pot a ball "on", it being a red or nominated colour, the other player will come into play and the balls "on" are always the reds, as long as there are still reds on the table.

The alternation between red balls and colours ends when all reds have been potted and a colour is potted after the last red, or a failed attempt to do so is made. All six colours have then to be potted in the correct order (yellow, green, brown, blue, pink, black). Each becomes the ball "on" in that order. During this phase, when potted, the colours stay down and are not replaced on the table, unless a foul is made when potting the colour, in which case the colour is respotted.

When the colours have been potted, the frame is over and the player who has scored most points has won it (but see below for "The End of Frame" scenarios).

Fouls

A foul is a shot or action by the striker which is against the rules of the game.

When a foul is made during a shot, the player's turn is ended and he will receive no points for the foul shot. The other player will receive penalty points.

Common fouls are:
* failing to hit any other ball with the cue ball
* first hitting a ball "not-on" with the cue ball
* potting a ball "not-on"
* potting the white (in-off)
* hitting a ball other than the white with the cue
* making a ball land off the table
* touching a ball with something other than the tip of the cue
* playing a "push shot" - a shot where the cue, cue ball and object ball are in simultaneous contact
* playing a "jump shot", which is where the cue ball leaves the bed of the table and jumps over a ball (even if touching it in the process) before first hitting another ball
* playing a shot with both feet off the ground

Should a cue ball be "in-hand", i.e. when breaking-off or playing from the "D" after being potted, be touched with the tip, a foul is not committed as long as the referee is satisfied that the player was only positioning the ball, and not playing, or preparing to play, a shot.

When a foul is made, the other player will receive penalty points. Penalty points are at least 4 points and at most 7 points. The number of penalty points is the value of the ball "on", or any of the "foul" balls, whichever is highest. When more than one foul is made, the penalty is not the added total — only the most highly valued foul is counted.

Not hitting the ball "on" first is the most common foul. Players can make life difficult for an opponent by making sure that they cannot hit a ball "on" directly. This is most commonly called "snookering" your opponent or alternatively "laying a snooker" or putting the other player "in a snooker".

Since players receive points for fouls by their opponents, snookering your opponent a number of times in a row is a possible way of winning a frame when potting all the balls on the table would be insufficient for you to win.

If a player commits a foul, and his opponent considers that the position left is unattractive, he may request that the offender play again from that position.

If a foul has been committed by not hitting a ball "on" first, or at all, and the referee judges that the player has not made the best possible effort to hit a ball "on", and neither of the players are in need of snookers to win the frame, or would be after the penalty points were applied, then "foul, and a miss" is called. In this instance the other player may request that all balls on the table are returned to their position before the foul, and the opponent play the shot again. (In top class play, this will usually require only the cue ball and a couple of other balls to be moved.) It should be noted that this rule is often applied less stringently, if at all, in amateur matches.

When a player leaves an opponent unable to hit both lateral extremities of at least one ball "on" after a foul, the opponent will receive a "free ball". This means any colour can be nominated and played as the ball "on". The number of points for potting the free ball is not the worth of the nominated ball but of the original ball "on". For example, if the ball "on" is a red, and the free ball is a pink, the player will receive one point for potting the pink. After potting the free ball as a red, a player can nominate and pot a colour as usual. The only exception to this rule is if the "on" ball is a red that is being obstructed by another red. For example, if the player breaking-off hits the white too soft and it does not hit the triangle of reds, a free-ball would not be called, even though no red can be hit on both sides, since the only thing preventing some of the reds being hit on both sides is another red.

Free ball

Free ball occurs after a foul shot where the resultant layout of the table leaves the opponent snookered (unable to hit any legitimate ball on either side). The opponent of the player who committed the foul can choose any other ball on the table as a replacement for the ball in question, and pot this as if it were the intended ball. If this was a red, then he continues to pot a colour which is, if successful, followed by another red etc.

If free ball occurs with all 15 reds still on the table, it gives a chance to an offended player to compile a break higher than 147 (147 is achieved by potting 15 reds and 15 blacks with all colours afterwards); in theory a break of 155 could be played but it has never been achieved in a professional tournament.fact|date=March 2008 However, breaks of 149 and 148 did occur in a professional tournament and Jamie Cope managed a 155 break, but only in a practice session.

It is allowed to play a snooker using the free ball, providing the snooker is not behind the ball which has just been used as the ball 'on'. It is allowed to cannon a ball nominated as a red into another red, so as to pot this (a "plant").

A free ball scenario also occurs when the ball gets stuck at the edge of a pocket jaw in such a manner that the player is unable to hit any legitimate ball. In this case also the player can play by calling any other ball as the "on" ball.

Miss

A miss will be called if a player does not hit the ball "on" first and is deemed by the Cuegloss|Referee|referee to not have made a good enough attempt at the shot. This gives his opponent the option to have the balls replaced as they were and have the fouling player take his shot again. A miss would not normally be called should the offending player require snookers, but there are exceptions to this scenario. Firstly, it may be possible to make full central contact on the ball "on" with a plain straight stroke, in which case a miss would be called every time an unsuccessful attempt at hitting it was produced. Secondly, it is still up to the referee's discretion whether an adequate attempt at hitting the object ball was made. If the referee deems that the snookered player has made no genuine effort to hit the ball, a miss can still be called despite snookers being required.

The rule was introduced to prevent players from playing cuegloss|Professional foul|professional fouls, i.e. deliberately fouling so as to leave the balls in a safe position, reducing the risk of giving a frame-winning chance to the opponent. Multiple misses often occur because players attempt to hit a shot thinly, in situations where such a contact would leave their opponent no potting chance. This can lead to a relatively easy full-ball Cuegloss|Escape|escape being retaken several times, as players feel that it is better to concede many points but leave a safe position, than concede none and leave a frame-winning chance.

However, the applied interpretation of the rule has proved controversial, as players sometimes narrowly miss a shot many times. Sometimes this is due to pure bad luck, or the difficulty of the snooker - meaning that a good snooker can pay more dividends than a great pot.

The end of a frame

If the score is tied after the final black is potted, the black is "respotted" and the cue ball put "in hand". The referee will then toss a coin, with the player winning the toss choosing who will take first strike at the black. Play then continues normally until the black is potted or another frame-ending situation occurs. A frame normally ends in one of three ways:

* A concession, when one player gives up due to being too far behind to have a realistic chance of winning the frame (usually when at the Cuegloss|Snookers required|snookers-required stage).
* When the pink is potted in the final stage of the frame, and the potting player leads by more than seven points as a result. The striker may pot the black, for example to complete a high-scoring break, if he so desires.
* The final black is potted legally (including after a respot), and the seven points scored puts one player ahead.

There are three less common ways to end a frame:

* A foul on the black, when the seven-point penalty puts the opposing player ahead by any score. It is sometimes wrongly assumed that play continues after a foul on the black if there are less than seven points between the scores. This is not the case: the player who has made such a foul loses the frame.
* Failure to hit a ball "on" three times in a row, if the player has a clear sight of the ball. The referee will warn a player after a second such miss that a third miss will mean forfeiting the frame. This rule does not apply if the player is snookered. As missing due to avoiding a direct shot on a ball is usually a tactical, rather than skill-related, outcome, this rule is rarely invoked, as a player will simply hit the ball directly on the third shot.
* If the referee deems a player is taking too long to take his shot, the player may be warned. If the player continues to hesitate, the frame may be awarded to the other player at the discretion of the referee. In practice, a delay of over two minutes can result in such a forfeiture.

Highest break

The highest break that can be made under normal circumstances is 147. To achieve that, the player must pot all 15 reds, with the black after every red, followed by potting the six remaining colours. This "maximum break" of 147 rarely occurs in match play.

If an opponent fouls before any balls are potted, and leaves the player a free ball, the player can then nominate a colour and play it as a red ball. Then, black can be nominated as the next colour. This means it is actually possible to score the value of 16 reds and blacks (16 * 8), plus the values of all the colours (27), which equals 155 points scored. This has never been done in a professional tournament. The highest break in tournament play is 149, and the highest break in professional matchplay is 148.

References

External links

* [http://www.worldsnooker.com/rules_of_snooker.htm World Professional Billiards & Snooker Association complete official rules]