The apex must be as close as possible to the pink ball without touching it. In nine-ball games where a handicap is given by one player being spotted a ball, some tournament venues enforce a rule that the spotted ball must be racked as one of the two balls in the row directly behind the 1 ball. And while there are lots of different types of billiard games that you can learn and play, pool is by far the most popular, at least in America. You can turn them into a ping pong table, or change them out for any number of other games. In practice, of course, locks aren't perfect: the pin holes in the plug are slightly out of alignment with respect to the shell and the pins and pin holes are each of a slightly different diameter. And, of course, electronic locks have at their root software whose size and complexity grows as they become more sophisticated (and as they are networked into centralized control systems).

For space flight, nitrocellulose was used by Copenhagen Suborbitals on several missions as a means of jettisoning components of the rocket/space capsule and deploying recovery systems. Nitrocellulose lacquer is spin-coated onto aluminium or glass discs, then a groove is cut with a lathe, to make one-off phonograph records, used as masters for pressing or for play in dance clubs. Play then continues with the cue ball shot from where it rested and the fifteenth ball from where it rested prior to racking. 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. Some players (most often amateurs) place the balls in numeric order but for the 9 ball; from the top of the triangle down and from left to right, i.e., the 1 on the foot spot, followed by the 2 then 3 in the second row, what is billiards and so on. An easy way to remember these positions is with the mnemonic, 'God Bless You', with the first letter of each word being the first letter of the three colours as they are racked from left to right on the baulk line.

Traditionally, the 1 ball is placed on the rack’s right corner, and the 5 ball on the left corner from the racker's vantage point to maximize contrast between the corner balls and the background, as the 1 and 5 are the brightest colored balls, however, the world standardized rules do not require this. However, after several missions and flights, it proved not to have the desired explosive properties in a near vacuum environment. However, all balls other than the 1 and 9 may be randomly placed. After the initial rack, the balls are played until only the cue ball and one object ball remain on the table's surface. A number of rules have developed which detail what must be done when one or both of the cue ball and fifteenth object ball are either in the rack area at the time an intragame rack is necessary, or are in such close proximity to the intragame racking area, that the physical rack cannot be used without moving the one or the other. In nine-ball, the basic principles are the same as detailed in the eight-ball section above, but only balls 1 through 9 are used; the 1 ball is always placed at the rack's apex (because in nine-ball every legal shot, including the break, must strike the lowest numbered ball first) over the table's foot spot, and the 9 ball is placed in the center of the rack.

Coloured ball racking positions must be remembered with care, as each time a coloured ball is potted, it is immediately replaced to its starting position, which occurs multiple times per frame, whereas reds are not returned to the table's surface after being potted. If the starting position spot for a coloured ball is covered by another ball, the ball is placed on the highest available spot. The cue ball, as always, is white. Further up the table is the pink ball, which sits midway between the blue spot and the top cushion, followed by the red balls (one each), placed in a tightly-packed triangle behind the pink. 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 (black end) cushion, without touching another ball. In both one-pocket and bank pool all fifteen object balls are racked entirely at random, with the center of the apex ball placed directly over the foot spot.