How Billiard Tables Work

Billiards, commonly known as pool, is an indoor sport that is played throughout the world. Many restaurants, bars and pubs have billiard tables, and the popularity of billiard tables in private homes is increasing.

Even if you haven't played billiards, you've probably seen most of the commonly used equipment, including the billiard table. In this article, you will learn about the tables used in billiards. You will discover how they are put together and learn about slate. You will also learn about the components of a table such as rails, pockets and the felt cloth that covers the table. And you will find out about the various games and how they differ from each other.

Basic Equipment

Billiards defines any game played on a table with a cue and balls. Billiards is a game that relies on the fundamentals of physics and geometry, and becoming an expert in billiards requires skillful mastery of the game's equipment. This equipment includes:

Balls - Although each variation of billiards has different rules, the goal is always to strike the a ball and move it in some fashion.
Cue - A long, tapered rod that has a cushioned tip on the narrow end for striking the balls.
Table - The playing surface that the balls travel on. Depending on the game it is designed for, the table may or may not have pockets (holes) for the balls to fall into.

Games played on tables with pockets are often referred to as pool or snooker, while the most common pocketless table game is called carom.

Next, let's take a look at the "cool" playing surface of the billiard table.

A Clean Slate

The playing surface of a billiard table has traditionally been made using a large slab of slate. Slate is a bluish-gray rock that cleaves (splits naturally) in broad, flat segments. Mainly composed of chlorite, mica and quartz, slate is formed when layers of clay sediment (the soil and debris that settles at the bottom of a body of water) with large concentrations of these minerals are compressed into sedimentary rock. The sediment hardens in thin layers as it compresses, creating a very hard rock with hundreds of naturally flat layers.

Slate can be ground and polished into a perfectly flat surface fairly easily, which is why it is sought after for billiard tables. Slate can be found all over the world, but major exporters include Italy, Brazil, China and India. The best slate for billiard tables comes from the Liguarian region of northern Italy. Because of this, Italian slate is preferred for a quality billiard table.

The cost of transporting slate due to the size and weight add considerably to the overall cost of a quality table. The slate is normally three-quarters of an inch to 1-inch (1.9 cm to 2.54 cm) thick and weighs between 400 and 600 lbs (181.4 kg to 272.1 kg). To make it easier to transport and less prone to fracturing from stress, the slate is normally split into three slabs, each about 150 to 200 lbs (68 kg to 90.7 kg). While this makes it much easier to move and set up, the three-slab version requires some work to ensure that the three slabs match perfectly and are flat all the way across. A few manufacturers use a single, large piece of slate instead of three pieces, but the three-slab method is generally preferred.

**The slate should be framed on the underside with wood.**

Ideally, the slate should be oversized. This means that the slate is slightly larger that the actual playing surface so that it extends beneath the rails of the table, providing additional strength to the rails. Most quality tables have the slate framed as well, with a wood backing glued to the underside of the slate. The felt cloth that is stretched over the slate is stapled or tacked to the frame. Without the frame, the cloth would have to glued directly to the underside of the slate.

The slate is carved out around the edges where the pockets will go. Also, holes are drilled along the edge so that the slate can be bolted to the top of the table frame.

**Italian slate is considered the best slate to use because it absorbs water better than any other type. This means that there are few problems with dampness or humidity affecting the cloth.**

Inexpensive recreational billiard tables use non-slate playing surfaces, including

Slatron and Permaslate - Hard, synthetic materials that are basically sheets of plastic layered over particle board
Honeycomb - A stiff plastic honeycomb structure between two sheets of plastic
Medium Density Fiberboard (MDF) - A flat piece of material made from compressing tiny pieces of wood together, also called pressed wood or particle board

The biggest problem with non-slate surfaces is that they warp easily and don't have the durability to maintain a perfectly flat playing surface for any length of time.

The quality of the playing surface doesn't matter unless it has a solid foundation to support it. In the next section, we will look at the construction of the table itself.

A Solid Foundation

The table cabinet starts with a large, rectangular, wooden frame, typically made of thick hardwood planks. Usually, there are one or more cross beams, along with a center beam, to provide additional support to the slate. The frame is connected at the corners either with metal brackets or wooden blocks. The metal brackets or wooden blocks are placed in each corner and bolted to the planks, forming a very solid frame.

Depending on the size of the table, and the thickness and weight of the slate, there will be four, six or eight legs supporting the table. Some designer tables replace the legs with a large pedestal base. Table legs can be hollow or solid, although solid legs are the preferred choice. While the legs may just go to the bottom of the frame, most experts agree that solid legs that extend to the underside of the slate provide the best support.

A billiard table factory is essentially a specialized woodshop. The process goes like this:

A good billiard table has a grid of wooden support beams to hold the slate.
©2001 HowStuffWorks.com

The table cabinet normally falls into one of five categories:

Laminate - MDF with a paper or plastic woodgrain glued on the exposed surface; normally found on inexpensive non-slate tables
Wood Veneer - MDF or solid wood with a thin piece of hardwood glued to the exposed surface; found on inexpensive to moderate tables
Wood-on-Wood - Quality hardwood glued on top of another type of wood; found on moderate to good-quality tables.
Solid Hardwood - Entire cabinet made of quality hardwood, such as oak, tulipwood or mahogany; found on top-quality tables
Metal-on-Wood - Sheets of metal, such as aluminum, attached to a wooden frame; found on commercial tables

Most billiard tables have drop pockets, which simply means that some type of net or container is under each pocket to catch the balls that fall into that pocket.

Some tables, particularly commercial tables, have a ball return.

The Path of Least Resistance

If you look inside a commercial table, there is a system of chutes that connect to the table's six pockets. Each chute is angled slightly downward from the pocket to the ball return. When a ball falls into that pocket, gravity causes it to roll along the guide until it reaches the ball return.

A pocketed ball is sent to a collection chamber where the balls line up single-file in a trough. These numbered balls remain locked in the chamber, which you can see behind a piece of Plexiglas, until someone wants to play a game and inserts some coins. By placing coins in a slot and pushing the coin arm in, you trip a lever that allows the balls to roll out of the trough into a large open access area at the foot end of the table.

**A coin-slot mechanism uses a lever to open the chute, allowing the balls to fall into the access area.**

Cue Balls

If a player accidentally pockets the cue ball (an act known as a scratch), the cue ball needs to come back out from the access area at the foot of the table. For the most part, coin-operated tables use two types of cue balls that can be easily separated:

An oversized ball that is separated by a radius gauging device.
A magnetic cue ball that triggers a magnetic detector.

The oversized ball is approximately 2-3/8 inches (6 cm) in diameter, which is about one-eighth of an inch (2 mm) larger than a normal ball. This slight difference in size allows the cue ball to be separated before it gets to the storage compartment. The smaller numbered balls are able to pass through a gauging mechanism, while the larger cue ball is directed through a second chute, where it falls out into an opening on the side of the table.

For players who dislike using the slightly larger cue ball, there are also coin-operated machines that can use a magnetic ball, in which a magnet is built into the core of the cue ball. Magnetic cue balls that go into a pocket are separated from numbered balls by a magnetic detector. As the magnetic ball passes this detector, the magnet triggers a deflecting device that separates the cue ball and, again, sends it into the opening on the side of the table.

**The cue ball returns to a small opening at the head end of the table.**

Both the oversized and magnetic cue balls can be used interchangeably on most of today's coin-operated tables, but each has its shortcomings. If you are a beginning pool player the larger ball might not affect your play, but it can disrupt the play of some advanced players who are used to playing with the normal 2 1/4-inch diameter (5.7cm) cue ball. Likewise, some players will notice a difference in the properties of a magnetic ball, which sometimes lacks a true roll. Also, because the magnetic ball has the magnetic material inserted into it, it has a greater tendency to shatter if dropped on a hard surface.

Whether the table uses drop pockets or an automatic ball return, the components on top of the table are the same.

Rails, Cushions and Felt

All around the edge of a billiards table are rails. Ranging from about 2.5 to 3.5 inches (6.35 cm to 8.89 cm) in width, the rails are normally made of the two pieces. The top part is made of the same hardwood or other material as the rest of the table. Glued to the bottom of this is a piece of of wood or MDF that the cloth will staple to when it is stretched over the cushion.

The cushion is a long, wedge-shaped piece of hard rubber that is glued to the side of the rail that faces into the table's playing surface. Cushions are covered with the same felt cloth used to cover the slate and should provide a consistent response to any ball that strikes them. All good tables will have K-66 cushions, which refers to the shape and angle of the cushion rubber.

**Cushions are made of hard rubber, and are glued to the rail. Canvas is then glued to the rubber to keep it from bouncing more than once when a ball strikes the cushion.**

Attached to the outside of each rail is the apron. Also called the blind, this is a strip of wood that matches the rest of the table. It is designed to hide the outside edge of the rail and should be very firmly secured to the rail.

The cloth is made of wool and nylon. In this picture, you can also see one of the inlays. Inlays are normally made of mother-of-pearl or plastic, and are used as reference points in most billiards games.

The final piece of the table is the cloth. Billiard tables normally use tightly-woven cloth made primarily of wool with a synthetic such as nylon added for durability. The cloth provides a consistent and smooth playing surface. Billiard cloth is often referred to as felt, but it actually is nothing like real felt. Real felt is not a woven material but is formed from compressed and matted fibers and would not work well at all as a smooth playing surface.

Now that you know how the table is made, what can you do with it?

Rack 'Em Up

There are a variety of games played on billiard tables. The games are split into two general categories: pocket billiards and carom billiards.

Pocket billiards

Called pool by most people, pocket billiards has six holes (pockets): one in each of the four corners and one in the middle of each long side of the table. An interesting fact is how the name pool came about. As pocket billiards increased in popularity in England in the late 1800s and early 1900s, gambling houses called pool rooms installed the tables as another form of entertainment. They were called pool rooms because people would place bets into a common fund ("pool") that would pay out to the winners. Eventually, the billiards tables proved so popular that they became the predominant entertainment at these establishments and the name "pool room" came to refer to a place where you played pocket billiards, and therefore pocket billiards became "pool."

8-ball - Arguably the most popular billiards game in the United States, 8-ball uses 15 numbered balls and a cue ball. One player attempts to "pocket" (put the ball in a hole) balls 1-7 and the other player tries to make balls 9-15. When a player makes all seven of his balls, the player attempts to make the 8 ball in a specific pocket. If he does so and does not also pocket the cue ball, he wins the game.

9-ball - One of the quickest and simplest forms of billiards, 9-ball uses 9 numbered balls and a cue ball. Players are required to shoot at the lowest ball on the table, beginning with the 1 ball. Whichever player makes the 9 ball in a way that is within the rules wins the game.
Snooker - While 8-ball is the game in the United States, English players favor this game, which uses 21 colored balls and a cue ball. 15 of the balls are red and count as one point each when pocketed. The other balls include one each of yellow, green, brown, blue, pink and black, with point values ranging from 2-7 respectively. A player must first make a red ball before attempting to pocket any of the other colors, which must be made in order of their value. When a player is left without a clear shot, they are said to be "snookered." The term "snooker" originally referred to a recruit in the British Army, where this game originated.
Straight pool - Also known as 14.1 continuous pool, straight pool uses 15 numbered balls and a cue ball. A player attempts to make the balls in any order, but must specify which ball and what pocket he plans to make it in. When there is only one ball left on the table, the other 14 are racked again and the player attempts to break them apart while making the other ball. A point is given for each ball made with the required number of points to win normally set at 150.
One pocket - This game is played with 15 numbered balls and a cue ball. Before play commences, the first player chooses one of the corner pockets at the foot end of the table. His opponent then has the other corner pocket at that end. Each player attempts to make balls in their pocket, gaining a point for each one made. Points are subtracted for making balls in other pockets or scratching (making the cue ball).
English billiards - Played with only three balls, there are also three specific ways to score. The player can make the ball he strikes deflect off another ball and into a pocket. He can hit one ball and make it strike the other two balls. Or he can strike a ball and make it knock another ball into a pocket.

Carom Billiards

These games are played on tables without any pockets. Both variations are played with three balls, one white, one red and a white ball with a red spot.

French billiards - The player chooses one of the two white balls as his cue ball. He must then cause the cue ball to hit the other two balls.
Three-cushion billiards - This variation requires that the cue ball strike one or more cushions three times before contacting any object balls.

Table Designs

There are nearly as many types of tables as there are variations on billiards.

The information below lists the specifications of some of the more common table designs.

Snooker

12 ft (3.7 m) x 6.1 ft (1.9 m)
Pockets

English billiards

12 ft (3.7 m) x 6.1 ft (1.9 m)
Pockets

Carom professional

10 ft (3 m) x 5 ft (1.5 m)
No pockets

Tournament

9 ft (2.7 m) x 4.5 ft (1.4 m)
Pockets

Carom standard

9 ft (2.7 m) x 4.5 ft (1.4 m)
No pockets

Pro-8

8.3 ft (2.5 m) x 4.15 ft (1.25 m)
Pockets

Standard

8 ft (2.4 m) x 4 ft (1.2 m)
Pockets

Bar

7 ft (2.2 m) x 3.5 ft (1.1 m)
Pockets

Economy

6 ft (1.8 m) x 3 ft (0.9 m)
Pockets

The tables listed above are the most common, but you can find billiards tables in all shapes and sizes. A version that you sometimes see is called bumper pool and has rubber columns (bumpers) arranged on the playing surface. Most of these tables are round or octagonal in shape and have one or more pockets between the bumpers.

Billiards is an exciting and challenging sport that can be enjoyed by everyone. If you can hold a cue and hit the balls with it, you can play a basic game of billiards. But, like any worthy skill, excellence at the sport does require practice and an understanding of the equipment.

For more information on billiards and related topics, check out the links on the next page.