Definition of Balk

Named after Chicagoan J. E. Parker, it is a 3½ × 7 inch box drawn on a balkline table from the termination of a balkline with the cushion, thus defining a restricted space in which only a set number of points may be scored before one ball must be driven from the area. Now supplanted by anchor spaces, it was developed to curtail the effectiveness of the anchor nurse, which in turn had been invented to exploit a loophole in balkline rules: so long as both object balls straddled a balkline, there was no restriction on counts, as each ball lay in a separate balk space.

A ball that is easily made from many positions on the table but which is left untouched while the rack is played, so that in the event the player gets out of position, the shooter has an insurance shot. Typically an insurance ball will be in or near the jaws of a pocket.

American CueSports Alliance. Their mission statement is "To heighten the interest and awareness of cue sports through the support and sanctioning of organized competition throughout the United States and North America."

In pool, the degree to which racked balls move apart upon impact by the cue ball as a result of a break shot.
In snooker, a shot sending the cue ball into the pack of red balls and separating them (after potting the ball-on). At least one split is usually necessary in each frame, since the original triangle of reds does not allow any balls to be potted reliably.

A thin sheet of rigid material in the size and shape of a physical ball rack (e.g. a diamond for nine-ball), with holes drilled though it, which is used to make permanent divots in the cloth of the table, one at a time for each ball in the racking pattern, by placing a ball in one of the holes in the carefully placed template and tapping it sharply from above to create the cloth indentation. The holes are spaced slightly closer than the regulation ball width of 21/2 inch (57.15 mm) apart, so that when the balls settle partially into their divots, the outer sides of these indentations create ball-on-ball pressure, pushing the balls together tightly. The purpose of the template is to do away with using a physical rack, with racking instead being performed simply by placing the balls into position, and the divots aligning them into the tightest possible formation automatically. This prevents accidental loose racks, and also thwarts the possibility of cheating by carefully manipulating the ball positions while racking. The European Pocket Billiard Federation (EPBF, Europe's WPA affiliate organization) has adopted this racking technique for its professional Euro-Tour event series.

The profile of the shaft of the cue as it as it increases in diameter from the tip to the joint. A "fast" or "slow" taper refers to how quickly the diameter increases. A "pro" taper describes a shaft that tapers rapidly from the joint size to the tip size so as to provide a long, untapered stroking area.

This is a special shaped leather or plastic bottle that is used on the table during play in special pocket games.

A predetermined number of games, usually played for a specified sum of money. Contrast race (a predetermined number of wins). Informally, sets may refer to gambling more generally, as in "I've been playing sets all day", even when the format is actually races or single games.

To elevate the back of the cue on a shot.

This is to lay down the money on the table in a betting game before play begins to ensure pay up at the end.

This is an attempt where one player answers the other players successful shot or run with a successful shot or run.

A directional pile created by the short fuzzy ends of fibers on the surface of cloth projecting upward from the lie and which create a favorable and unfavorable direction for rolling balls. The convention in most billiards games in which directional nap cloth is used is to brush the cloth along the table in the same direction of the nap, usually from the end that a player breaks. In snooker and UK eight-ball especially, this creates the effect of creep in the direction of the nap, the most-affected shot being a slow roll into a center pocket against the nap. It is commonly referred to in the fuller term "nap of the cloth." When nap is used in relation to woven cloths that have no directional pile, such as those typically used in the U.S. for pool tables, the term simply refers to the fuzziness of the cloth.

American Poolplayers Association. This is the largest association of pool players in the world, and includes The Canadian Poolplayers Association. With numerous tournaments, including the U.S. Amateur championship, they are a force on the competition scene.
The APA has established the use of the "Equalizer" which offers handicaps to players and equalizes the playing field like in golf.

Linen made from flax and produced in Ireland which is often used to wrap the gripping area of the butt of a cue.

A term used in snooker for the potting of all the balls that are racked at the beginning of the frame in a single break (run). The minimum total clearance affords 72 points (barring multiple reds being potted on a single stroke), in the pattern of red then yellow repeatedly until all reds are potted, then all of the colour balls. The maximum break is 147 (barring a foul by the opponent immediately before the break began).

Also smalls, small ones, small balls. In eight-ball, to be shooting the solid suit (group) of balls (1 through 7); "you're the small one" or "I've got the smalls". Compare little, solids, reds, low, spots, dots, unders; contrast big.

A point bead on a scoring string.

This is placed on a ball by hitting it slightly below center. This action makes the ball travel in a motion against its originally hit direction.

Any mechanical aid that serves to extend the length of the player's cue, normally added to the end of the butt either by clipping around the end or screwing into the base. Though extensions are used for pool, it is more common in snooker because of the significantly larger table size.
In a tournament where players get limited time to make their shots (common in televised matches), an extension is extra time granted before making a shot; players have a limited number of extensions in each frame.

A gentle tap of the cue ball with the intention of getting it as tight as possible behind another ball, in the hope of a snooker. It is most common in the game of snooker, and is illegal in many pool games, in which on every shot a ball must either be pocketed, or some ball must contact a cushion after the cue ball has contacted an object ball.

The forward rotation of the cue ball that results from a follow shot. Also known as top spin or top, follow is applied to the cue ball by hitting it above its equator, causing it to spin more rapidly in the direction of travel than it would simply by rolling on the cloth from a center-ball hit. Follow speeds the cue ball up, and widens both the carom angle after contact with an object ball, and angle of reflection off a cushion.

In snooker, the abandonment of a frame upon agreement between the players, so that the balls can be set up again and the frame restarted with no change to the score since the last completed frame. This is the result of situations, such as trading of containing safeties, where there is no foreseeable change to the pattern of shots being played, so the frame could go on indefinitely.
In pool, placing of the object balls back in the rack, after a foul break.

This is a low bet in a game with action.

A predetermined, fixed number of games players must win to win a match; "a race to seven" means whomever wins seven games first wins the match.