Editing Diving (sport) (section)

===Dive numbers===
In competition, the dives are referred to by a schematic system of three- or four-digit numbers. The letter to indicate the position is appended to the end of the number.

The first digit of the number indicates the dive group as defined above.

For groups 1 to 4, the number consists of three digits and a letter of the alphabet. The third digit represents the number of half-somersaults. The second digit is either 0 or 1, with 0 representing a normal somersault, and 1 signifying a "flying" variation of the basic movement (i.e. the first half somersault is performed in the straight position, and then the pike or tuck shape is assumed).  No flying dive has been competed at a high level competition for many years.

For example:
* 101A – forward Dive Straight
* 203C – back one-and-a-half somersaults, tuck
* 305C – reverse two-and-a-half somersaults, tuck
* 113B – flying forward one-and-a-half somersaults, pike
* 104C – front double somersaults, tuck

For Group 5, the dive number has 4 digits. The first digit indicates that it is a twisting dive. The second digit indicates the group (1–4) of the underlying movement; the third digit indicates the number of half-somersaults, and the fourth indicates the number of half-twists.

For example:
* 5211A – back dive, half twist, straight position.
* 5337D – reverse one and a half somersaults with three and a half twists, in the Free position.

For Group 6 – Armstand – the dive number has either three or four digits: Three digits for dives without twist and four for dives with twists.

In non-twisting armstand dives, the second digit indicates the direction of rotation (0 = no rotation, 1 = forward, 2 = backward, 3 = reverse, 4 = inward) and the third digit indicates the number of half-somersaults. Inward-rotating armstand dives have never been performed, and are generally regarded as physically impossible.

For example:
* 600A – armstand dive straight
* 612B – armstand forward somersault pike
* 624C – armstand back double somersault tuck

For twisting Armstand dives, the dive number again has 4 digits, but rather than beginning with the number 5, the number 6 remains as the first digit, indicating that the "twister" will be performed from an Armstand. The second digit indicates the direction of rotation – as above, the third is the number of half-somersaults, and the fourth is the number of half-twists:

e.g. 6243D – armstand back double-somersault with one and a half twists in the free position

All of these dives come with DD (degree of difficulty) this is an indication of how difficult/complex a dive is. The score that the dive receives is multiplied by the DD (also known as tariff) to give the dive a final score. Before a diver competes they must decide on a "list" this is a number of optional dives and compulsory dives. The optionals come with a DD limit. this means that a diver must select X number of dives and the combined DD limit must be no more than the limit set by the competition/organisation etc.

Until the mid-1990s the tariff was decided by the FINA diving committee, and divers could only select from the range of dives in the published tariff table.  Since then, the tariff is calculated by a formula based on various factors such as the number of twist and somersaults, the height, the group etc., and divers are free to submit new combinations.  This change was implemented because new dives were being invented too frequently for an annual meeting to accommodate the progress of the sport.