Makin Every Second Count

Implementation of the Smart Rings Jury Tool to Evaluate Hold Time during the

Men’s Artistic Gymnastics European Championships 2016

M. J. J. J. Aarts

, L. A. J. Wolfs

and A. H. M. Pluk

InnoSportLab‘s-Hertogenbosch – Innovation in Gymnastics, Marathonloop 7a, ‘s-Hertogenbosch, The Netherlands

Royal Dutch Gymnastics Federation (KNGU), Lage Bergweg 10, Beekbergen, The Netherlands

1 OBJECTIVES

Within competitive gymnastics, a still rings routine

consists of swing, strength and hold elements (FIG,

2015). The difficulty and execution of these

elements is evaluated by a panel of judges. Although

the human eye can distinguish quite accurately

between different elements and whether an element

is correctly executed, internal research by the

European Gymnastics Union (UEG) has shown that

the timing of the strength and hold elements is less

accurate. Consistent and precise timing of these

elements is crucial, because a deduction of 0.3 point

must be given when the Hold Time (HT) is less than

2.0 seconds. This deduction could make a big

difference as can be seen in small gaps of the scores

of the still rings final at the EC in 2014 and 2015:

0.200 point between first and fifth place and 0.333

point between second and last place respectively)

(UEG, 2014; UEG, 2015).

A digital support tool, Smart Rings Jury Tool,

was developed to support the evaluation of HT. The

aim of this study was to implement and evaluate this

tool during the Men’s Artistic Gymnastics (MAG)

European Championships 2016.

2 METHODS

During the European Championships Gymnastics

2016 in Bern (Switzerland) the Smart Rings Jury

Tool was implemented in the junior MAG

competition. For the senior MAG competitions

datasets and jury evaluations were collected, but

implementation of the tool in competition was not

allowed due to Olympic regulations.

For both rings, force transducers connected

directly to the cables of each ring were built in the

upper beam of a FIG certified still rings apparatus of

Spieth. The forces exerted by the gymnast were

captured with a sample frequency of 1 kHz together

with 50 Hz reference video and automatically saved

to a measurement computer. A modified computer

mouse was connected as a measurement tool to

manually start and stop the timing. A computer

screen, placed on the jury table, presented the force

signals, the video of the gymnast and the judges

expert input (Figure 1).

Next to the regular jury panel, two HT judges

were assigned to evaluate HT with the Smart Rings

Jury Tool. The left mouse button was pressed by one

of the judges at the start of a correctly executed

strength or hold element, the button was held during

the element and was released when the hold ended

or when the element was not held in the correct body

position anymore. After the exercise both judges

evaluated the HT by checking the screen, where the

duration of the judges input was presented within the

graph of the force signals. The judges input signals

became green if the duration was 2.0 seconds or

longer (Figure 1).

Figure 1: Part of the user interface of the Smart Rings Jurytool, showing the negative force signal (blue line), expert input

(red and green blocks), hold time indication (text after blocks) and reference video (right).

Aarts, M., Wolfs, L. and Pluk, A.

Makin Ever y Second Count - Implementation of the Smart Rings Jury Tool to Evaluate Hold Time during the Men’s Artistic Gymnastics European Championships 2016.

In Extended Abstracts (icSPORTS 2016), pages 29-30

Table 1: Number of exercises, number of holds, holds per exercise, hold errors by Smart Rings and actual deductions given

by the jury during the Junior (Junior CI) and Senior qualifications (Senior CI) and total (Junior CI and Senior CI combined).

Number of

exercises

Number of

holds

Holds per

exercise

Hold errors Smart

Rings

Deductions

Junior CI

123 587 4.77 57 (9.7%) 63 (10.7%)

Senior CI

91 559 6.14 116 (20.7%) 104 (18.6%)

Total

214 1146 5.36 173 (15.1%) 167 (14.5%)

3 RESULTS

During the European Championships 2016 in Bern,

278 complete datasets of ring exercises were

recorded, of which 214 datasets of the qualifications

(CI). As can be seen in Table 1, within these 214

qualification exercises, 1146 hold elements were

executed. On average, in 15.1% of these hold

elements a hold error was reported by the Smart

Rings Jury Tool (which means the button was

pressed for less than 2.0 seconds), while in 14.5% of

the hold elements indeed a deduction was given after

evaluation of the judges. This shows the benefit of

the combined force and video signals.

The above statistics show that in Senior

competition a larger number of hold elements are

performed per exercise, but also a higher percentage

of hold errors were found by the Smart Rings Jury

Tool (9.7% and 20.7% respectively) and consequen-

tly also a higher percentage of deductions were

given after evaluation (10.7% and 18.6% respective-

ly). This indicates that implementation of the tool

during Senior competition is even more important

for accurate and objective evaluation of strength and

hold elements.

In Junior CI on average 18.4% (7.1%-32.1%) of

the total deduction consisted of HT deductions,

proving that it is a very important aspect of still

rings judging.

4 DISCUSSION

In this study the expert input of the judge is used to

determine for what period all criteria (i.e. body

position) for a strength or hold element are met. A

previous study of Aarts and Pluk (2015) showed that

a fully automatic evaluation of HT based on force

was not able to check these criteria. Also slow

transitions between strength elements were difficult

to detect with an automatic system.

There are some differences between the HT

errors reported with the Smart Rings Jury Tool and

the actual deductions given after evaluation. This

might appear due to an interruption in the hold

element: it can be decided to release the button if an

element does not meet all criteria anymore and start

pressing again after correction. In this case, the

judge would have pressed twice within one element

and only one deduction of 0.3 points can be given. It

also occurred that a jury incorrectly started pressing

when it turned out not to be a hold or strength

element. In those cases no deductions were given.

In this implementation, the two HT judges were

allowed to discuss during evaluation of the HT

decisions of one judge. It might be preferable to

have two separate judges’ evaluations and take the

average, or discuss those differences. Overall, the

Smart Rings Jury Tool proved to be a precise and

consistent way to evaluate HT.

ACKNOWLEDGEMENTS

This project was supported by the Community of

North Brabant and Sportinnovator in The

Netherlands.

REFERENCES

FIG (Fédération Internationale de Gymnastique), 2015.

Code of Points Men’s Artistic Gymnastics.

UEG (Union Europeenne de Gymnastique), 2014. MAG

ECh SOFIA Media Book. Retrieved from http://www.

ueg.org/media/results/850/MAG_ECh_SOFIA_Media

_Book.pdf

UEG (Union Europeenne de Gymnastique), 2015. Result

book ECh AG Montpellier 2015 Media Book.

Retrieved from http://www.ueg.org/media/results/987/

Result%20book_ECh_AG_Montpellier_2015_Media_

Book.pdf

Aarts, M.J.J.J., Pluk, A.H.M., 2016. “Hawkeye” for

gymnastics: Automatic evaluation of hold time in a

still rings exercise during the European Champion-

ships gymnastics 2014. Science and Engineering

Conference on Sports Innovation, April 8, 2016,

Amsterdam.

icSPORTS 2016 - 4th International Congress on Sport Sciences Research and Technology Support