64 on the official ranking list, or finishing as one of the top eight prize money earners during the most recent season, guaranteed a tour place for the next season, this being assessed after the World Championship. If, after a foul, the next player cannot cleanly strike both sides of the object ball, the referee may call a free ball, allowing the player to nominate any other ball in place of the object ball they might normally have played. These are shots that are designed to make playing a legal shot harder, such as leaving another ball between the cue ball and the object ball. If a player is awarded a free ball with all 15 red balls still in play, they can potentially make a break exceeding 147, with the highest possible being a 155 break, achieved by nominating the free ball as an extra red, then potting the black as the additional colour after potting the free-ball red, followed by the 15 reds with blacks, and finally the colours. A maximum break in snooker is achieved by potting all reds with blacks, then potting all six colours, yielding 147 points; this is often known as a "147" or a "maximum".

Although some success was achieved with this format, it did not receive the same amount of press attention or status as the regular ranking tournaments. The World Championship uses a longer format, with matches ranging from the best of 19 frames in the first round to best of 35 for the final, which is played over four sessions of play held over two days. The UK Championship, held annually since 1977, is considered to be the second most important ranking tournament, after the World Championship. Some early world finals had much longer matches, such as the 1947 World Snooker Championship, what is billiards which was played over the best of 145 frames. Most matches in current professional tournaments are played as the best of 7, 9, or 11 frames, with finals usually the best of 17 or 19 frames. A snooker match generally consists of a predetermined number of frames. If you’ve stepped into a billiards showroom or even done some online browsing for pool tables, you’ve probably noticed that there are an overwhelming number of felt colors to choose from. Many pool tablesare built with the underside of the playing surface somewhat exposed.

While standard CFL bulbs are not dimmable, but you can find dimmable versions on the market, which may be important to create a nice pool playing ambiance. Both billiards and pool can be further classified into cue games, which is one of the main similarity between the two. This, sometimes called "throw," is hard to master, but it can be very useful during the course of a game. As a particularly dramatic example of the latter, predictions on the consequences of a nuclear war (the so called Nuclear Winter) have been refined in detail since the first Conference on the Global Consequences of a Nuclear War (Washington 1983). There is always, however, room for speculation on the reliability or accuracy of any simulation made by computer, because even tiny changes are cumulative, and after many passes those changes take their toll and give a totally different result (the so called Butterfly Effect). Originally intended for batch processing, it was the first non-symbolic language of high level, targeted to problems.

A player could achieve a break of 15, for example, by first potting a red followed by a black, then another red followed by a pink, before failing to pot the next red. A foul can occur for various reasons, such as sending the cue ball into a pocket, or failing to hit the object ball. The latter is a common foul committed when a player fails to escape from a "snooker", where the previous player has left the cue ball positioned such that no legal ball can be struck directly in a straight line without being wholly or partially obstructed by an illegal ball. Players can qualify for the tour by virtue of their position in the world rankings from prior seasons, by winning continental championships, or through the Challenge Tour or Q School events. This event has been taken out of the tour since 2013, when the Champion of Champions was established.