MINILAB | Some debate on Young's 3A on Beijing olympics

According to You Young's short program results at the Beijing Olympics, the 3A (triple axel) seems to have been marked downgrade as follows.

In figure skating, all jumps are marked as follows: "graded, under rotated, down grade". Down below is an image of its mark: graded, down graded, under rotated, (topdown, respectively). The criteria below are the criteria for landing in counterclockwise rotation. (Note that landing baseline is 12 O' clock direction)

Many figure skating fans claim that the results differ upon on where referees take the ascending point and landing point. In fact, I've seen a lot of figure skating for almost 13 years, it sure is hard to judge axel jump other than toe jumps, so I analyzed based on images claimed by fans.

Environment

Metrabs is used to estimate human pose in this case.

• GPU: NDIVIA 1060Ti
• CPU: intel i7
• OS: Window10
• IDE: CoLab

Trial #1

In the case of claiming the starting point of the axel as where the skidding starts, the results below are as follows.

When the axel is calculated from the start of skidding, the direction vector (red one) of the left foot and the direction vector (blue one) of the right foot when jumping are as follows.

The angle between the two is about 88 degrees. As landing criteria is opposite side of the starting point, adding 180 degrees to the as start point of the axel is the case. In turn, the result is 92 degrees, which is over 90 degrees, so it becomes Underrotated

However, other address that start point should take further ahead. (Trial #2)

Trial #2

A lot of people say the footage in landing was right in Trial #1.
Considering this, let's look at the results below.

In this case, the angle between the two is about 1 degree, and considering that the landing point is wrong, let's say it's 6 degrees (plus 5 degrees). Likewise, the correct landing point of the axel is added by 180 degrees to the starting point. So in this perspective, You's 3A is marked down graded at 186 degrees under circumstances.

Wrap up & Conclusion

Last year May 2021, Figure skater, 2018 olympic champion, Hanyu Yuzuru addressed the need of artificial intelligence in figure skating judge system through his graduate thesis. Not only in figure skating, many sports event mark poorly on asian just because of its race.
Even if someone in future make an AI referee, I am highly doubt that if there is any point on making fair judge system in this certain point.

" Athlete who violates doping cannot compete in the game. This principle must be observed without exception. All players' efforts and dreams are equally precious. - Yuna Kim"