Definition of lost their stroke

A player who was playing very well but suddenly starts playing badly. e.g. "He was making everything on every shot, then lost his stroke and couldn't hit anything, costing him the match."

24 Random Essential Billiards Terms

Describes lucky or unlucky "rolls" of the cue ball; "I had good rolls all night; "that was a bad roll." However, when said without an adjective ascribing good or bad characteristics to it, "roll" usually refers to a positive outcome such as in "he got a roll".
The roll: same as the lag.
The Billiards World Cup Association. The Billiards World Cup Association (BWA) was a governing body for carom billiards, like its competitor and successor, Union Mondiale de Billard. After staging several three-cushion billiards championships, BWA met its demise in 2004 due to financial problems and failing relations with the UMB, leaving the latter as the only carom governing body.
Sometimes called a snake shot. A carom billiards shot, common in three-cushion billiards, where the cue ball is shot with reverse english at a relatively shallow angle down the rail, and spins backwards off the adjacent rail back into the first rail.
This is a term used to refer to all the different aspects involved in setting up a shot, i.e. the stance, grip, bridge, and stoke.
A type of spin imparted to the cue ball to make it rebound from a cushion at a shallower angle than it would if the spin had not been used.
The object ball involved in a key shot.
Name for the ball that when pocketed, wins the game, or any ball that when made results in a payday such as a way in the game of Chicago.
When the contact between the cue ball and object ball is dead center.
During a set if the opponent does not win a single game, they are said to have been skunked.
Also topspin, top-spin, top. Same as follow. Contrast bottom spin, back spin.
This is the act of looking over the stack, pile of balls in the middle of the table, to see if there are any opportunities in the game of one pocket.
Modification of the rules and/or scoring of a game to enable players of variable abilities to compete on a more even playing field. Examples of handicapping include spotting balls and giving games on the wire to an opponent. In league play, other forms of handicapping include awarding compensating points to a lesser-skilled team, or using numerical player ranking systems to adjust final scores between opponents of different skill levels.
This is a tool used to keep your cue tip from mushrooming. This small tool slides over the tip and turns to refine the sides, keeping your tip shaped the way it should be.
This is a toned down masse shot. The cue is elevated a little and will curve a little in the direction the spin is applied. This is used to sneak around difficult shots.
Also piquet. Either a massé shot with no english, or a shot in which the cue stick is steeply angled, but not held quite as vertical as it is in full massé.
The pocket chosen to house the selected ball in your called shot.
The overall competition between two players, two pairs of players or two teams of players, usually consisting of a predetermined number of frames or games (sometimes organized into rounds).
The non-red colored ball meant to be pocketed in a game of snooker, or the next ball meant to be pocketed in a particular game.
This is a long distance shot that is given to your opponent as a challenge to make because it often works well as a safety (defense) when a better one is not available.
The ball required to guarantee victory in a match. Sometimes used figuratively to mean the last difficult ball required (chiefly British and usually used in multi-frame matches, particularly snooker).
In snooker and other British usages, a break of 50-99 points (100 points or more being called a century), which involves potting at least 12 consecutive balls (i.e. the last 3 reds with at least 2 blacks and a pink, followed by all the colours).
Two or more object balls that are touching or are close together.
Also yellow(s).
In snooker, the lowest-value colour ball on the table, being worth two points. It is one of the baulk colours.
In blackball, one of two groups of seven object balls that must be potted before the eight ball; compare stripes; contrast red ball.
Also massé shot. A steep curve or complete reversal of cue ball direction without the necessity of any rail or object ball being struck, due to extreme spin imparted to the cue ball by a steeply elevated cue. For Example: shooting with extreme english by holding the cue at a position of 30-90 degrees while applying left or right spin.