Definition of Flat back pack

This is English that turns into running action after contact with the object ball. This will open up the angle on a bank.

The inside walls of a pocket billiards table's pockets.

This is a style of playing a pool game with a partner playing on your team. You can either take turns or play in a tag team style. This works well when there are a lot of people around that want to play.
A form of team play in which two players compete against another team of two players in any given frame or match. In a doubles game, the first player from the breaking team is the only one who shoots during the opening inning, with control of the table passing to a member of the opposing team at the end of that inning, then upon the end of the opponent's inning to the doubles partner of the original player, and next to the second opponent, play proceeding in this doubly alternating manner until concluded. Contrast Scotch doubles.

Sandbagging, in any handicapped sport, is the unethical practice of deliberately playing below your ability in order to alter your handicap so it does not reflect your true ability.

A player's auction at a pool tournament. Each player is called and players and spectators bid on the player. The highest bidder(s) pays their bid to the calcutta, and by doing so invest in that player's success. If a player wins or places in the tournament, those who "bought" the player receive a percentage of the total calcutta payout, usually tracking the percentage payout of the tournament prize fund. Typically, players have the option of purchasing half of themselves when the high bid is won by a third party. Like english and scotch doubles, usually not capitalized.

Also nurse shot, nursery shot. In carom games such as straight rail, balkline and cushion caroms, where all the balls are kept near each other and a cushion, and with very soft shots, can be "nursed" down a rail on multiple successful shots that effectively replicate the same ball setup so that the nurse shot can be repeated again (and again, etc.). Excessive use of nurse shots by players skilled enough to set them up and pull them off repeatedly at will is what led to the development of the balkline carom billiards game variations, and repetitive shot limitation rules in English billiards. A clear example of why: In 1907, Tom Reece scored a record break of 499,135 consecutive points over a period of five weeks, without a miss, using the cradle cannon nurse shot.

Used with an amount to signify money added to a tournament prize fund in addition to the amount accumulated from entry fees (e.g. "$500 added").

Also double-century break. In English billiards, a break of 200-299 points (i.e. double a century). Larger multi-centuries are regularly achieved. Rare in amateur play, triple centuries are routine, and quadruples not uncommon at World Professional Billiards Championships; 2007 winner Mike Russell shot four triples in the final round alone, while of sixteen competitors, three shot quadruple centuries (one once, one twice, and Russell three times). Quintuple centuries are rare even at the professional level, with only the 494 shot by nine-time World Champion Russell (who has more such titles than any other player in history as of 2007) coming close in that event. World Champion Geet Sethi holds the world record, at a duodectuple century (and then some) of 1276 consecutive points."

This is to step up to the table and successfully execute a difficult shot.

Chiefly American: Also known as side spin, english (which is usually not capitalized) is spin placed on the cue ball when hit with the cue tip to the left or right of the ball's center. English has a marked effect on cue ball rebound angle off cushions (though not off object balls), and is thus crucial for gaining shape; and can be used to "throw" an object ball slightly off its otherwise expected trajectory, to cheat the pocket, and for other effects. "English" is sometimes used more inclusively, to colloquially also refer to follow and draw. In combination one could say bottom-right english, or like the face of a clock (4 o'clock english). The British and Irish do not use this term, instead preferring "side".

A shooter's body position and posture during a shot.

In the UK, one of the two pockets one either side of a pool, snooker or English billiards table halfway up the long rails.

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, a phrase used to describe a situation where the player has an easy pot and in general the balls are in a position to go on to make a sizeable break.

Any shot where the cue ball is intentionally jumped into the air to clear an obstacle

Term for object balls in the game of Chicago that are each assigned as having a set money value; typically the 5, 8, 10, 13 and 15. In games where multiple balls must be pocketed in succession to score a point, such as cribbage pool or thirty-ball, when the last ball necessary to score has been potted, the points given is referred to as a way.

This refers to the cluster of balls remaining in a similar position to where they were within the break.

This game is played on a smaller octagonal table filled with bumpers in the middle and two more bumpers surrounding a hole on each side of the table. The game is played by trying to sink the balls into the opposite pocket by hitting the object ball directly instead of using a cue ball.

A tournament format in which a player must lose two matches in order to be eliminated.

This refers to the cluster of balls remaining in a similar position to where they were within the break.

In the UK, a long-distance shot played to pot a ball close to a pocket with heavy top spin, so that when the cue ball hits the cushion it bounces off but then stops due to the counteraction of the spin. It is not common in competitive play, being more of an exhibition shot.

A reference to the amount of English applied to the object ball from the cue ball.

Chiefly British: The rail at the Top of the table. Compare foot rail; contrast Bottom rail.

Chiefly British: Same as duck, and stemming from the same obvious etymology.