The first perfect ten in Olympic history was scored by Nadia Comaneci of Romania, on uneven bars during the compulsory round at the 1976 Olympic Games in Montreal. The last perfect ten in Olympic history was scored by Lavinia Milosovici, also of Romania, in the floor exercise event finals at the 1992 Olympic Games in Barcelona. Now, gone is the perfect ten. Starting in 2006, the FIG unveiled a brand new scoring system. This new scoring system continues to confuse people, especially casual fans who only watch gymnastics during the Olympics. I'll do my best to break it down in the plainest English possible so everyone understands.
The D-Score
The new system consists of two numbers, a D-score and an E-score. The D is for difficulty, which is the start value of the routine. It's calculated from the value of each skill performed plus five tenths for every requirement on each apparatus, and connection bonus. Each skill in the Code of Points has a value from A to G (or I on floor exercise), which is translated into tenths.
The top 8 most difficult elements are added together, with the connection bonus and 2.0 points for fulfilling each requirement to create a start value. Composition requirements for routines are further explained here, and connection values for routines are further explained here.
Let's take Mai Murakami's floor exercise from the 2017 World Championships, for example.
Dance element: quadruple turn (E)
First pass: double twisting double back (H)
Second pass: double layout (F)
Third pass: 2½ twist (D) + front full twist (C) [CV 0.1]
Two connected dance elements: switch split leap (B) + split leap with 1½ turn (D)
Dance element: double L-turn (D)
Fourth pass: double pike (D)
The top acrobatic elements would be:
double twisting double back - H
double layout - F
2½ twist - D
The top dance elements would be:
quadruple turn - E
split leap 1½ - D
double L-turn - D
The top optional elements (either acrobatic or dance) would be:
double pike - D
front full twist - C
Acro skills: H + F + D
Dance skills: E + D + D
Optional skills: D + C
0.8 + 0.6 + 0.4 + 0.5 + 0.4 + 0.4 + 0.4 + 0.3 = 3.8
Connection values: 0.1
3.8 + 0.1 = 3.9
3.9 + 2.0 = 5.9
Mai's start value is 5.9.
Start values vary for each apparatus. For example, on vault, the start value for the Amanar (2½ twisting Yurchenko) is 5.8. The hardest start value is a 6.4, which applies to the Produnova (handspring double front) and the Biles (Yurchenko half-on, double twist off).
To medal on bars, the start value needs to be in the mid to high 6's. Beam and floor are pretty similar. To medal, the start value needs to be in the mid 5's to low 6's.
The E-Score
The E is for execution. The execution is out of a ten, which is simple enough to understand, so I don't need to explain that. These also vary for each apparatus, with vault being the highest-scoring event and floor being the lowest, due to the deductions gymnasts take for stepping back on their tumbling passes and pausing in the corner too long before a tumbling pass.
With the new scoring system, no one has been awarded a perfect execution score. A few have come close. Nastia Liukin and He Kexin were the only gymnasts to score in the 17's on uneven bars during the 2005-2008 quad. McKayla Maroney’s near-perfect vault in team finals in London had a 9.733 in execution. Simone Biles also had execution scores in the mid to high 9's on vault (as high as 9.700 internationally).
And Finally
Let's go back to Mai Murakami's floor exercise. Her start value is a 5.9. Her execution score during the event finals at the World Championships was 8.333. Add them together and you get 14.233. That is her final score.
Solid scores start at about the mid-13 range. Scores in the 14's are very good and scores in the 15's are excellent. Anything lower than around 12.500 is considered a miss.
For the TL;DR Crowd
If you completely skipped over everything (I don't blame you, it's confusing):
- Scores are made by adding up two numbers: the difficulty, or start value, and the execution, which is out of a 10. Final scores range from 12 to 15, depending on the start value.
- Scores in the mid to high 13's are solid and consistent. The middle of the pack.
- Scores in the 14's are very good. 14's win medals.
- Scores in the 15's are exceptional. 15's win gold medals.
- Anything lower than 12.500 is not good.
If a gymnast falls, they can still medal if their start values are high enough (see: Vanessa Ferrari 2006 AA, Li Shanshan 2007 BB EF, Cheng Fei 2008 VT EF, Rebecca Bross 2009 & 2010 AA, Yao Jinnan 2011 AA, Aliya Mustafina 2012 AA, McKayla Maroney 2012 VT EF).