Definition of Key ball

A shot played slowly and with heavy draw and follow-through so that the cue ball can be struck firmly but with a lot of the pace taken out, allowing more control than just a gentle tap that would travel as far. Also called "Drag Draw".

To play a shot with the stroke and speed that makes it easiest to pocket the object ball, even at the expense of sacrificing position.

A common aiming method in which a phantom ball is imagined frozen to the object ball at the point where an imaginary line drawn between their centers is aimed at the desired target; the cue ball may then be shot at the center of the "ghost" ball and, ideally, impact the object ball at the proper aiming contact point. The ghost ball method of aiming results in misses where adjustment is not made for collision induced throw.

This describes a shot in carom games where the cue ball is driven all the way across the long rail, crossing the table, to score a point.

A phrase used in snooker to describe the scenario whereby there are not enough available points on the table to level the scores for the frame, therefore the trailing player needs his/her opponent to foul in order to be able to make up the deficit. The name comes from the fact that this would normally have to be achieved by placing the leading player in foul-prone situations such as difficult snookers.

This is the playing surface for billiards games. Consisting of 6 pockets, cushions on the side, and a felt layer covering the hard table portion, the length is usually twice as long as it is wide, but varies depending on the game at hand.

This is a certain type of system used to determine who plays first in the next game. These methods are not synonymous with pool skills, and are more along the lines of flipping a coin, paper-rock-scissors, or drawing straws.

A style of game play in which as many players are allowed to join as the participants choose, and anyone can quit at any time. The term, most often used in the context of gambling, is borrowed from poker. The folk games three-ball and killer are usually played as open ring games, as is Kelly pool.
By extension, a multi-player game that anyone may initially join, but which has a fixed roster of competitors once it begins, is sometimes also called a ring game. Cutthroat is, by its nature, such a game. A famous regular ring game event of this sort is the Grady Mathews-hosted six-player, $3000-buy-in ring ten-ball competition at the annual Derby City Classic.
A nine-ball ring game is played by more than two players. Safeties are not allowed.

Chiefly British: bank shot played up and down the longer length of the table off a short rail and into a corner pocket, as opposed to the more common bank across the short length into a center pocket or corner.

When a particular ball is given as a handicap in nine-ball, designating that ball in turn means that it must be made in rotation, when it is the lowest numerical ball remaining on the table, and cannot be made to garner a win earlier in the game by way of a combination, carom or any other shot. For example, if a player is spotted the 8 ball, he only wins by making that ball after balls 1 through 7 have been cleared from the table.

The 'Lady Jane Grey' is a rarely used term to describe a shot in the game of snooker. The cue ball is baulk side of the spotted black after potting a red ball. The black is powerfully potted into a top corner pocket and the cue ball bounces off the top cushion into the red balls, moving them into space, thus allowing the continuation of a break. Named after Lady Jane Grey, the 16th Century Queen of England, possibly because the speed the cue ball must be hit matches the speed with which she was deposed from the throne.

The Union Mondiale de Billard (French for World Union of Billiards) is the world governing body for carom (carambole) billiard games. The organization was founded in Madrid, Spain on 1 June 1959, and is dedicated to promoting the modern carom billiards games. The UMB monitors and controls international carom competitions and tournaments, and organizes an annual World Three-cushion Billiards Championship.

Also simply maximum. In snooker, the highest break attainable with the balls that are racked; usually 147 points starting by potting fifteen reds, in combination with blacks, and clearing the colours. Also called a 147 (one-four-seven). In six-red snooker, the maximum break is only 75 points, due to fewer red balls and thus fewer black-scoring opportunities.

This is a location where a player can go inexpensively to refine their pool skills. These establishments began as horserace betting houses, and are still often filled with games involving money action. If you get thirsty, many pool halls offer cold refreshments, however, be careful you are not there just for the refreshments. In that case, you may as well be playing at a bar with a bent cue on a rain table.

Certain rules say you must designate your shot before taking it. Generally this is just calling the ball to be sunk in which pocket, and is not dependent on touching rails or other balls, but very well can be.

Any ball that may be legally struck by the cue ball.

During a set if the opponent does not win a single game, they are said to have been skunked.

When the cue ball contacts three or more cushions in carom games.

This is the act of keeping your ball location advantages the way they are, and not allowing your opponent to even things out in the game of one pocket.

The area on the table behind the head string.
The origin of the term has been the subject of some speculation but the best explanation known is that in the 1800s, many homes did not have room for both a billiard table and a dining room table. The solution was a billiards table that had a cover converting it into a dining table. Kept in the dining room, play on such a table was often restricted by the size of the room, so it would be placed so that the head rail would face the connected kitchen door, thus affording a player room for the backswing without hitting a wall. A player was therefore either half or sometimes fully (literally) "in the kitchen" when breaking the balls.

The first shot in a game - aimed at a set of racked balls.
To execute the first shot in a new game.
In snooker this term can be use to indicate a series of successive shots completed by a single player.

A 7 inch (17.8 cm) square box drawn on a balkline table from the termination of a balkline with the rail, thus defining a restricted space in which only 3 points may be scored before one ball must be driven from the area. It developed to curtail the effectiveness of the chuck nurse, which in turn had been invented to thwart the effectiveness of the Parker's box in stopping long, repetitive runs using the anchor nurse.

Shooting at an object ball that is already in motion at the moment of shooting and cue ball impact; illegal in most games and usually only seen in exhibition/trick shots.

This is a bank in one pocket pool that is sitting at an angle that makes it unsafe to play.