Gymnastics scoring system

Before the change, gymnastics scores were compiled by using a “start value” that measured the difficulty of the routine and then taking deductions from that start value for errors in execution. In the 1990s, the ten became more and more difficult to achieve because as difficulty increased, few gymnasts actually started from a ten, and those gymnast who were performing the most difficult routines would have trouble performing them perfectly.

In the new system, there are two separate scores, one for difficulty and one for execution. Two separate panels of judges evaluate the difficulty and execution of the routine, and the two scores are added together. The goal of this system is to focus more on the artistry and value of the performance as a whole. Difficulty: The “A” Score

Though the difficulty of a routine can be determined in advance, the two judges on the “A” panel evaluate the routine as it is actually performed. Certain errors can reduce the difficulty level of an element or eliminate it from the score entirely. Examples include under-rotation, incorrect body position, or a fall. Deductions may be taken from both the A score and the B score for certain errors.

On all apparatus but the vault, credit is given both for the difficulty of each element (A through G, from .10 to .70) and for certain combinations of elements (.10 or .20). Errors between elements such as a pause or a balance check can take away credit for the combination. Repeated elements do not lead to credit for the individual elements, but a repetition can be used in combination. Credit is given only for the eight or nine most difficult individual elements, depending on the apparatus, as well as for the dismount. There is also a credit of .50 for each Element Group Requirement performed, up to five per routine.

On the vault, difficulty is predetermined based on the entry, the number of rotations and saltos (flips), and the direction of flight. For team finals and all around, gymnasts perform one vault each. For event finals, gymnasts perform two vaults and they must have a different direction in the second flight phase or one vault must not have any saltos in the second flight phase. Execution: The “B” Score

The “B” panel consists of six judges, each of whom awards a score for the execution of the routine. Like the old system, this score starts from ten and errors lead to deductions. There are suggested deductions for each type of error, and maximum deductions are specified in the Code of Points. The highest and lowest scores are dropped and the middle four scores are averaged. If the difference between those four scores is greater than a certain acceptable deviation, the Apparatus Supervisor also has the option to ask a judge to change his score.

While many deductions reflect purely technical errors, other are aimed at the artistry of the routine, such as poor rhythm or additional hops or swings. If there are errors in the composition of the routine, such as too few release moves on bars or insufficient use of the entire apparatus on beam, a deduction is taken from the A score.

Source: http://gymnastics.suite101.com/article.cfm/the_new_womens_gymnastics_scoring_system

That was a great explanation but I would like to add that this scoring system is not just for the Olympics. It is for every gymnastics competition.