Automated scoring for elite half-pipe snowboard competition: important sporting development or techno distraction?

Abstract

We previously reported a strong relationship between video-based objective data (air time and degree of rotation) and subjectively-judged scores awarded during elite half-pipe snowboard competitions. Advancements in sport-monitoring technologies now provide the capacity to accurately and automatically quantify this objective information. This may assist current subjective coaching and competition judging protocols provided the integration process imparts a large element of control to key players within the sport. We therefore recently hosted an invitational half-pipe snowboard competition (2007 Australian Institute of Sport Micro-Tech Pipe Challenge) designed to evaluate whether the snowboarding community would embrace a competition where results were in part determined by automated objectivity. We explored the practical, logistical, and technical challenges associated with conducting such an event and evaluated the relationship between subjective judging and results predicted from objective information to see if prior research had ecological validity. Ten elite, male half-pipe snowboarders were instrumented with inertial sensors throughout this competition. A prediction equation using previously-established weightings of average air time and average degree of rotation accounted for 74 per cent of the shared variance in subjectively-judged scores awarded during this competition. Although our predictions of overall scores and rankings were good, 26 per cent of the total variance was still unexplained. This should not be considered a weakness of this approach, but a strength, as the subjective components of style and execution should never be removed from the sport. The future of half-pipe snowboarding, however, may be best guided a judging protocol that incorporates both objective and subjective criteria. © 2008 John Wiley and Sons Asia Pte Ltd

1. INTRODUCTION

1.1. Overview

The snowboarding practice community perceives air time and degree of rotation as important components in successful half-pipe riding; however, athletic training progression and competition performances are currently assessed by purely subjective measures. We previously provided quantitative evidence of the effect air time and degree of rotation has on competition performance that supports this practice community perception. Furthermore, both of these objective performance variables can now be calculated and classified using basic signal processing of inertial sensor data. Such sport-specific automated objectivity is theorized to enhance training and competition performance assessment protocols; however, it is imperative that key members within the sport be part of any integration process. We recently conducted an invitational half-pipe snowboard competition in collaboration with the practice community that required athletes to compete while wearing inertial sensors. The main purpose was to evaluate the utility of microtechnology to enhance current subjective judging protocols and to compare scores predicted from purely objective data to the subjectively-established scores and rankings made by an expert judge. In addition, we hosted a special event where the overall rankings were established entirely based on inertial sensor data to gauge the acceptance of this objective evaluation technique within the sport of half-pipe snowboarding.

1.2. Elite-Level Half-Pipe Snowboarding

Snowboarding was originally a counter-culture recreational activity derived from surfing and skateboarding. Antagonistic to the accepted use of alpine ski resorts around the time of the sporting discipline's inception, snowboarding was initially banned in most ski resorts. Snowboarding has subsequently been somewhat partitioned from the skiing fraternity ever since. The sport, however, has been a part of the Winter Olympic competition program since the 2002 Winter Olympic Games held in Nagano, Japan. Snowboard half-pipe courses are shaped like a long half-cylinder and are usually created from large amounts of snow that is shaped into the preferred profile using specially-designed snow groomers. Although the dimensions vary within different ski resorts, Federation International de Ski (FIS) World Cup and Winter Olympic snowboard half-pipes are commonly 160–200 m long, 18 m wide, situated on transitions of approximately 18 degrees, and have wall transitions of 5–6 m. Recent developments within the sport, however, have seen the introduction of grooming machines capable of creating wall transitions of 7–8 m (Figure 1). Half-pipe snowboarding is a sporting discipline where athletes are required to perform an aerial acrobatic routine on a half-pipe snowboard course made of snow. The aerial acrobatic routines performed by half-pipe snowboard competitors are currently judged in competition by a purely subjective measure termed “overall impression”. This performance assessment measure takes into account a large number of sport-specific components, such as the amplitude, degree of rotation, difficulty, style, and execution associated with each aerial acrobatic maneuver; the sequence and combination of aerial acrobatic maneuvers; the amount of risk in the routine; the overall use of the half-pipe, including the line taken through the course; and how the run progresses and flows. Half-pipe snowboarding has until recently received very little attention from scientists and the subsequent focus on objectifying sport-specific parameters in the quest to enhance athletic performance and assist elite-level judging protocols.

Figure 1. Current Olympic standard snowboard half-pipe in Calgary Olympic Park. Half-pipe has been shaped by the new 22-foot Zaugg pipe cutter (generating wall transitions of approximately 7–8 m) and will most likely be the size and shape of the half-pipe course that will be used in the 2010 Winter Olympics in Vancouver. Reproduced by kind permission of Ben Alexander 2008.

1.3. Automated Objectivity: Air Time

There is evidence from coaches, judges, and spectators that suggests that air time (Figure 2) and amplitude are crucial components of half-pipe snowboarding competitive success 1, 2. The components of air time and amplitude, however, are currently assessed subjectively by elite-level coaches and competition judges when providing performance feedback to athletes. We have previously shown that air time can be objectively calculated using video-based analysis and that there is a significant and large linear relationship (r=0.56±0.26, P<0.001, r²=0.31, Standard error of the estimate (SEE)=4.60, n=30) between total air time and an athletes subjectively-judged score during two FIS World Cup half-pipe snowboarding competition finals held in Bardonecchia, Italy in 2005 3. It is believed, however, that the use of video analysis to objectively calculate information on air time during half-pipe snowboarding would be difficult to incorporate on a routine basis. This is a result of the labor-intensive nature of the manual post-processing of video data and the subsequent time delay in information feedback. We therefore promoted the use of microtechnology to provide automated objective feedback on air time and recently showed that air time can be accurately and reliably calculated using inertial sensor output (provided by tri-axial accelerometers) and basic signal-processing techniques 3. This particular study showed a very large correlation (r=0.78±0.08, P<0.001, r²=0.61, SEE=0.08, n=92) between a criterion measure (video-based analysis) and novel technology-based (accelerometer signal-processing technique) methods. Approximately 95 per cent (94.57 per cent) of the accelerometer measures lie within ±0.15 s of the criterion measure. The two-pass signal-processing technique promoted within this study was able to detect 100 per cent of the aerial acrobatic maneuvers performed 3. The capacity of microtechnology and basic signal-processing techniques to accurately and reliably calculate air time for 100 per cent of aerial acrobatic maneuvers is theorized to allow successful integration of this concept into half-pipe snowboarding training and competition judging environments.

Figure 2. Australian athlete performing an aerial acrobatic maneuver (during a routine national team training session at Perisher Blue Ski Resort) focused purely on maximizing air time while ensuring the subjective components of good style and execution are not lost in the process. Image: Heidi Barbay 2007. Reproduced by kind permission of www.AnarchistAthlete.com

1.4. Automated Objectivity: Degree of Rotation

Air time is only one component of successful half-pipe snowboarding performance. The aerial acrobatics and the associated degree of rotation associated with those acrobatics (Figure 3) also contribute to a competitor's overall score. As is the case with air time, there is evidence that promotes the degree of rotation associated with each aerial acrobatic maneuver as an important component in successful half-pipe snowboarding 1, 2. We recently showed that there is a strong relationship (r=0.55±0.26, P=0.002, r²=0.30, SEE=4.63, n=30) between total degree of rotation alone and overall competition score during two World Cup finals in Bardonecchia, Italy in 2005 1. It is believed that for a given air time, an athlete that accumulates more degree of rotation will score better in competition, provided the aerial acrobatic maneuvers have been executed well. Similar to the case with air time, there is reason to believe that the automatic calculation of degree of rotation may prove beneficial in assisting elite-level coaching and competition-judging protocols by allowing the individuals in charge of assessing performance to focus on the more stylistic components of the sport. We recently showed that it is possible to automatically and reliably classify aerial acrobatics into sport-specific rotational groups by processing rate gyroscope data using integration by summation to provide a composite rotational parameter termed “air angle” (AA) 4. Provided rotations are performed predominantly around a single horizontal axis, the signal-processing method provides reliable classification of aerial acrobatics. Mean differences in AA measurement between preceding rotational groups (e.g. between 360 and 180, 540 and 360, and 720 and 540) were statistically significant (mean differences [±SEM] 180.67±21.36, 189.86±22.62, 176.74±11.64; P=0.004, P=0.002, and P<0.001, respectively). Of utmost importance, however, was the absence of overlapping AA measurement limits between different rotational groups. The absence of overlapping AA measurement limits affords some flexibility outside the statistically-derived likelihoods while still ensuring reliable classification of aerial acrobatics 4. Although the experienced snowboarding community are trained to recognize rotational aerial acrobatics, there is potential for automated acrobatic classification to provide continual performance assessment focused on the degree of rotation (albeit a purely objective assessment) without constant human attention. Coaches, judges, and support staff may thereby focus their attention on the more subjective aspects of performance.

Figure 3. Australian athlete performing an aerial acrobatic maneuver (during a routine national team training session at Perisher Blue Ski Resort) focused on achieving a high degree of rotation while ensuring air time, amplitude, and the subjective components of good style and execution are not lost in the process. Image: Heidi Barbay 2007. Reproduced by kind permission of www.AnarchistAthlete.com

1.5. Sociological Perception Toward Automated Objectivity

The key performance variables associated with air time and degrees of rotation are major components of successful half-pipe snowboarding competition performance. It is, however, important to note that the shared variance of subjectively-judged scores each objective variable explains seems to be dynamic and subsequently shifts according to a number of different factors, such as athletic field ability, environmental and snow conditions, and half-pipe course shape and size. There is evidence, however, that shows that air time and degree of rotation are always strongly and positively associated with subjectively-judged scores. Furthermore, these variables can now be assessed objectively by either video-based analysis or by utilizing the recent developments with microtechnology and basic signal-processing techniques. This objective assessment is theorized to provide coaches and competition judges access to performance feedback that until this point has been unavailable. There is, however, a potential issue associated with the integration of this concept. The most significant aspect of technological change in sport is that any integration can dictate the future of a sport in a way that makes reversing such changes very difficult 5. Technology can additionally have unintended negative consequences with the potential to effect change beyond its original purpose 5, 6. Half-pipe snowboarding is a sporting discipline that has assessed athletic performance with subjective measures since its inception, and currently prides itself on the provision of a competitive platform allowing individuality and athletic freedom of expression. It is believed that for any integration of automated objectivity to be successful within half-pipe snowboarding, a large component of control needs to be designated to key players within the sporting community (Figure 4). Although there is awareness that the focus on subjective perception of style and execution in the current competition judging system is unable to consistently identify correct competition results, there is also a strong and somewhat paradoxical community perception that this performance assessment focus is a major strength 1. There is therefore a dominant negative perception of a proposed automated judging concept based solely on objective information unless the system integrates with the current subjective-judging protocol and continues to allow athletic freedom of expression and the capacity for athletes to showcase individual style and flair in elite competition. Athletes, coaches, and judges are not totally opposed to the idea; however, there is a strong practice community perception that further development and integration of this concept be conducted in close association with core community members and be controlled from within the sport (Figure 4).

Figure 4. Australian athletes relaxing prior to the start of the Australian Institute of Sport Micro-Tech Pipe Challenge. It is imperative that sport scientists considering integrating any form of automated objectivity into elite-level snowboarding work alongside the practice community and allow key community members, such as athletes, coaches, judges, and the supporting industry, to play a major role in the overall direction. Image: Heidi Barbay 2007. Reproduced by kind permission of www.AnarchistAthlete.com

1.6. Australian Institute of Sport Micro-Tech Pipe Challenge

The 2007 Australian Institute of Sport (AIS) Micro-Tech Pipe Challenge (Figure 5) was the culmination of evaluations focused on the importance air time and degree of rotation have on half-pipe snowboard competition scores and the recent capacity to automatically calculate objective information on air time and degree of rotation using microtechnology and continual observation of the practice community's coveted future directions. The 2007 AIS Micro-Tech Pipe Challenge was an elite-level, Australian invitational half-pipe snowboarding competition that utilized both traditional subjective-judging measures and innovative microtechnology developed at the Australian Institute of Sport (Canberra, ACT, Australia), Griffith University's Centre for Wireless Monitoring (Brisbane, QLD, Australia) and Applications and Catapult Innovations (Melbourne, VIC, Australia) to assess half-pipe snowboarding performance. The event, conducted on 30 July 2007, is believed to be the first half-pipe snowboarding competition in Australia to utilize microtechnology-based objective feedback to award athletic performance. The 2007 AIS Micro-Tech Pipe Challenge was primarily a concept event designed to evaluate whether the snowboarding community would embrace a competition where results were in part determined by automated objectivity. The practical, logistical, and technical challenges associated with conducting such an event were also explored, and the relationship between subjective judging and results predicted from objective information was evaluated to see if prior research had ecological validity. This paper is focused primarily on the ecological validity of prior research and evaluates the relationship between subjectively-judged scores and results predicted from objective information using previously-established weightings.

Figure 5. Australian Institute of Sport Micro-Tech Pipe Challenge 2007 competition flier.

2. EXPERIMENTAL DESIGN

2.1. Subjects

Ten elite-level, male Australian half-pipe snowboarders were recruited and ultimately volunteered to participate in this study. Data collection was performed during the southern hemisphere winter season of 2007 on Monday, 30 July at Perisher Blue Ski Resort (Perisher Valley, NSW, Australia; altitude: 1720 m) on the resort's custom snowboard half-pipe (length: 80 m, width: 18 m, transition height: 5 m, gradient: approximately 15 degrees). Data collection was performed during a total of 50 competition runs. Experimental procedures were approved by the Ethics Committee of the Australian Institute of Sport on 18 August 2005 (reference no.: 20050808) and in accordance with Griffith University requirements, cleared under special review in January 2008 (reference no.: PES/01/08/HREC).

2.2. Equipment and Signal Processing

Previously-developed sensors 7–9 comprising of one tri-axial accelerometer (100 Hz±6 g) and one tri-axial rate gyroscope (100 Hz±1200 degrees s⁻¹, 20.94 rad s⁻¹) were used throughout the data collection and the associated competition. Sensors were attached to the lower back of each athlete, situated approximately 5 cm to the left of the spine as previously described 3 and as shown in Figure 6. Raw data was stored on board the sensor unit (256 MB Trans Flash) for the duration of the data collection process, sampled, and analyzed post-collection by a computer software suite developed in-house 8. Accelerometer components underwent two-point static calibration in three orthogonal axes (up/down, forward/back, and left/right) aligning each axis of sensitivity with and against the direction of gravity. Rate gyroscope components underwent a two-point calibration integrating angular velocity over time throughout 0 and 90 degrees in three orthogonal axes (yaw, pitch, and roll) prior to each data collection session 8, 10. Panning video footage of each half-pipe run was collected using a 3CCD 50 Hz digital video camera (TRV950E, Sony, Tokyo, Japan) from the bottom and centre of the half-pipe to provide feedback on style and execution to athletes and serve as a back-up method of key performance variable calculation in the advent of failure of any of the sensors.

Figure 6. Australian athlete preparing for the Australian Institute of Sport Micro-Tech Pipe Challenge while an inertial sensor unit is switched on by a project collaborator from Griffith University's Centre for Wireless Monitoring and Applications Department. Inertial sensor unit was mounted inside a small, padded carry bag and positioned on the lower back to the left of the spine. Image: Heidi Barbay 2007. Reproduced by kind permission of www.AnarchistAthlete.com

Data was processed with previously-documented methods of automated air-time calculation 3 and degree of rotation classification 4 in order to objectively assess these sport-specific key performance variables during an elite-level competition environment. We have previously shown 3 that basic signal-processing techniques can calculate air times associated with individual aerial acrobatic maneuvers. The air time-specific signal-processing technique is a two-pass method to detect the locations of half-pipe snowboard runs using power density in the frequency domain and a subsequent threshold-based search algorithm in the time domain which is focused on the detection of when a snowboarder leaves the snow surface on take off and contact the snow surface upon landing during half-pipe snowboarding. This technique correctly identified the air times of 100 per cent of aerial acrobatic maneuvers within each half-pipe snowboarding run (n=92 aerial acrobatic maneuvers from four subjects) and displayed a very strong correlation with a video-based reference standard for air-time calculation (r=0.78±0.08, P<0.0001, SEE=0.08×/÷1.16; mean bias=−0.03±0.02 s; value±or ×/÷95 per cent confidence limits) 3.

We have also previously shown 4 that basic signal processing of inertial sensor data can classify aerial acrobatic maneuvers into four sport-specific rotational groups (aerial acrobatics with 180-, 360-, 540-, or 720-degree rotations). Classification of aerial acrobatics is achieved using integration by summation. Angular velocity () quantified by tri-axial rate gyroscopes was integrated over time (t=0.01 s) to provide angular displacements (). Absolute angular displacements for each orthogonal axes (i,j,k) were then accumulated over the duration of an aerial acrobatic maneuver to provide the total angular displacement achieved in each axis over that time period. The total angular displacements associated with each orthogonal axis were then summed to calculate a composite rotational parameter (AA). We observed a statistically significant difference between AA across four half-pipe snowboarding acrobatic groups which involved increasing levels of rotational complexity (P=0.000, n=216) 4.

Sensors were switched on (Figure 6) and began collecting data at the beginning of the competition (8.30 hours) and were switched off and ceased data collection immediately after the competition's completion (11.00 hours). All objective data derived from microtechnology sensors were processed immediately following the competition and required approximately 1.5 h to generate a complete assessment of all objective information related to air time and degree of rotation.

2.3. Air Time and Degree of Rotation Definitions

This paper focuses on the utilization and promotion of objectivity in assessing half-pipe snowboarding performance. As such, the key performance variables of air time (Figure 2) and degree of rotation (Figure 3) and their associated subcomponents require definition for repeatable and reliable measurement. Air time begins the first moment there is no longer contact between the snowboard and the snow, and ends the moment any part of the snowboard comes in contact with the snow following an attempted aerial acrobatic maneuver. It is also believed there are additional variations in aerial acrobatic air time that have practical relevance to half-pipe snowboarding performance and will allow enhanced training and judging protocols. These variations also require definition to allow accurate and reliable assessment.

• Air time is measured in seconds and reflects the amount of time the athlete spends in the air during a half-pipe snowboarding aerial acrobatic maneuver, beginning the first moment there is no longer contact between the snowboard and the snow, and ending the moment any part of the snowboard comes in contact with the snow following an attempted aerial acrobatic maneuver.

• Total air time is measured in seconds and calculated by adding together all recorded air times (typically 6–8) during a half-pipe snowboard run 3.

• Average air time is also measured in seconds and is calculated by dividing total air time by the total number of aerial acrobatic maneuvers completed throughout the duration of a half-pipe snowboarding run 3.

• Highest individual air time is measured in seconds and is the individual aerial acrobatic maneuver performed throughout a half-pipe snowboard run that achieves the largest air time 3.

Rotation terminology used by half-pipe snowboarding practice communities is not based on an assessment of exact degree of rotation achieved. It is based on a sport-specific approximation that has been previously described 4. The take off, and more specifically, the landing angles (similar but opposite to the take-off angle) associated with half-pipe snowboarding aerial acrobatics generate a situation where the exact degree of rotation achieved will always be less than the terminology used to describe it. Theoretically, the degree of rotation achieved during rotations performed predominantly around a single axis is at least 90 degrees less than the rotation the athlete is credited with, based on conventional terminology. Rotational terminology can be based upon the following rules: an athlete will land, aerial acrobatics traveling in the same direction they were initiated with, in 180- (straight air), 540-, 900-, and 1260-degree rotations. In contrast, an athlete will land, traveling in the opposite direction of the initiation, during 360-, 720-, and 1080-degree rotations. These rules apply only in half-pipe and quarter-pipe snowboarding (result of take off and landing occurring on the same lip). Although snowboarders can ride forwards or backwards, these rules apply regardless of the direction of travel when aerials are initiated 4. As with air time, it is believed the key performance variable of the degree of rotation should be defined in order for sport scientists to accurately and reliably calculate the degree of rotation. The degree of rotation begins the first moment there is no longer contact between the snowboard and the snow and ends the moment any part of the snowboard comes in contact with the snow following an attempted aerial acrobatic maneuver. There are subcomponents of the aerial acrobatic degree of rotation that have practical relevance to half-pipe snowboarding performance and will allow enhanced training and judging protocols. These variations therefore require definition to allow accurate and reliable assessment:

• Degree of rotation is measured in degrees and reflects the amount of rotations (calculated using the rules 4 associated with the sport-specific approximations) an athlete completes during individual aerial acrobatic maneuvers performed during a half-pipe snowboarding routine. Note: aerial acrobatic maneuvers that contain no sport-specific rotational component (“straight airs”) still generate a degree of rotation value of 180 degrees by microtechnology and signal processing and should also be deemed a 180-degree rotation when using video-based analysis. This is because the athlete takes off and lands on the same half-pipe lip and therefore turns through approximately 180 degrees in the horizontal plane. The first aerial acrobatic maneuver with a sport-specific rotational component is a 360-degree rotation 4.

• Total degree of rotation is measured in degrees and calculated by adding together all recorded rotations associated with each aerial acrobatic maneuver performed (typically 6–8) during a half-pipe snowboard run.

• Average degree of rotation is also measured in degrees and is calculated by dividing the total degree of rotation by the total number of aerial acrobatic maneuver completed throughout the duration of a half-pipe snowboarding run

• Highest individual degree of rotation is measured in degrees and is the individual aerial acrobatic maneuver performed throughout a half-pipe snowboard run that achieves the largest degree of rotation.

• Highest cumulative degree of rotation is measured in degrees and is calculated by adding together the total degree of rotation associated with the largest consecutive series of rotational aerial acrobatic maneuvers. For example, this parameter is associated with the total degree of rotation related to aerial acrobatic maneuvers that contain a rotational component that are performed “back to back” or in a consecutive “group”. Athletes can perform a string or cluster of consecutive aerial acrobatic maneuvers that all possess a rotational component during a half-pipe snowboard run. Strings of consecutive rotational maneuvers can, however, be interspaced with what is termed a “straight air” or a “number of straight airs” (aerial acrobatic maneuvers that contain no rotational component) generating a half-pipe snowboard run containing a number of different clusters of “back-to-back” rotational acrobatic maneuvers. There is evidence 1, 2 that athletes who string together a consecutive series of aerial acrobatics with a high rotational component score highly in competition as sequences of consecutive rotational acrobatics increase the difficulty and risk associated with the routine. The highest cumulative degree of rotation is focused on the series of consecutively-performed rotational maneuvers that obtains the highest total degree of rotation throughout a half-pipe snowboard run. This is different to the total degree of rotation which simply adds together the degree of rotation associated with all aerial acrobatic maneuvers that have a rotational component performed within a completed half-pipe snowboard run, regardless of whether or not those rotational maneuvers were performed consecutively or “back to back”.

2.4. Competition Format and Judging

The purpose of this competition was to compare traditional subjective judging results with those predicted using purely objective data with no reference to style or execution. The competition also focused on an initial integration of automated objectivity into elite half-pipe snowboarding by awarding three separate prizes based on objective information judged solely by microtechnology. Competition performances judged purely by objective measures were: (i) highest average air time; (ii) highest average degree of rotation; and (iii) highest individual air time. A World Cup and Olympic Games snowboard judge was appointed as the sole judge for the traditional subjective judging component associated with this competition. Athletes were awarded an overall impression score out of 10 for each competition routine by this judge. Objective data were provided by post-event processing of microtechnology outputs. The athletes themselves were also asked immediately following the completion of the event to provide (anonymously) their selections associated with the top five athletic performances to award an athlete judged best rider. Athletes were provided with a 30-min warm-up period prior to the start of the competition. All athletes had access to “over-snow” transport (skidoo) providing them quick access to the top of the half-pipe following each warm up and competition run (Figure 7). Athletes were allowed three runs to contest the traditional subjective judging component of the competition, the objective judging components of highest average air time and highest average degree of rotation, and the athlete judged best rider. The objectively-judged highest individual air time was decided with an additional two-run format that immediately followed the main competition allowing each athlete the chance to perform only one aerial acrobatic maneuver per run with the specific instruction to complete straight airs focused on as much amplitude and air time as possible.

Figure 7. Australian athletes had access to “over-snow” transport during the Australian Institute of Sport Micro-Tech Pipe Challenge to allow for effective use of the practice session and to ensure the competition itself was run in an efficient manner. Image: Jason Harding 2007. Reproduced by kind permission of www.AnarchistAthlete.com

2.5. Predicted Scoring Using Objective Data

Predicted scores and rankings were calculated using objective data in a multiple regression prediction equation based on previously-established weightings. Previously-established weightings were derived from an unpublished video-based analysis of an elite-level event conducted on the same half-pipe almost a year earlier (Burton Australian Open 2006). The prediction equation included the key performance variables of average air time and average degree of rotation:

• (1)

where PS is the predicted score, the combined key performance variable AAT is average air time, and ADR is the average degree of rotation.

The prediction equation was determined by multiple linear regression (enter method) and displayed a very large correlation with subjectively-judged scores at the 2006 Burton Open conducted on the same half-pipe course (r=0.88±0.11, P<0.001, r²=0.77, SEE=2.82, n=28). Each run in the 2006 Burton Open event was scored out of 30; the 2007 AIS Micro-Tech Challenge event was scored out of a total 10 available points. The predicted score generated by the aforementioned regression was subsequently divided by a factor of 3. Data associated with predicted scores and subjectively-judged scores were then examined to determine retrospectively if rankings would be any different if entire scores were established using automated objectivity.

2.6. Statistical Analysis

This study allowed a criterion (subjectively-judged scores)-referenced validation of predicted competition scores (objective practical measure) associated with 18 cleanly-completed runs performed during the AIS Micro-Tech Pipe Challenge. Cleanly-completed runs were deemed to be competition aerial acrobatic routines performed without major mistakes, such as falls, stops, placing hands onto snow surface upon landing, and associated losses of momentum. All correlations are presented as correlation coefficient (r)±95 per cent confidence limits, P-value (P), goodness of fit (r²), standard error of the estimate (SEE), and sample size (n). All mean bias results are presented as mean bias±95 per cent confidence limits. All correlations, goodness of fit statistics, standard error of the estimates, and P-values were calculated using SPSS 13.0 for Windows (Graduate student version; SPSS, Chicago, IL, USA). All confidence limits and mean bias calculations were performed using Excel spreadsheets provided by Hopkins 11. All confidence limits were set at 95 per cent, and statistical significance was set at P<0.05. Stacked graphs were generated using Prism 4.01 (PRISM, La Jolla, CA, USA). The 3-D scatter graph was generated with triplet data sets using Sigma Plot 8.00 (Sigma Plot, San Jose, CA, USA).

3. RESULTS

3.1. Objective and Subjective Competition Data

The use of microtechnology-based automated objectivity can potentially allow coaches, athletes, and judges access to information pertaining to half-pipe snowboard competitions that has previously been unavailable. Table 1 shows the objective key performance variable information associated with total air time, average air time, highest individual air time, total degree of rotation, average degree of rotation, highest individual degree of rotation, highest cumulative degree of rotation, the subjectively-judged competition scores awarded for each run, and the overall position for each athlete. A total of 18 cleanly-completed runs out of a possible 30 were performed throughout the 2007 AIS Micro-Tech Pipe Challenge, and not all athletes were able to perform more than one completely-clean competition run. Any run deemed to have suffered falls, stops, major places of hands onto snow following aerial acrobatic landings, and associated losses of momentum were removed from the retrospective analysis. The scores shown in Table 1 were provided by the subjective judge throughout the competition. The objective key performance variable information shown in Table 1 was analyzed post-competition from data obtained from microtechnology sensors.

Table 1. Key performance variable information associated with each “clean run” during the Australian Institute of Sport Micro-Tech Pipe Challenge

Rider (bib no.)	Score (points)	Final ranking	TAT (s)	AAT (s)	HIAT (s)	TDR (d)	ADR (d)	HIDR (d)	HCDR (d)
^a Data is shown in descending order of subjectively judged score. Not all athletes completed more than one “clean run” throughout the competition. Subjectively-judged scores were generated by the competition judge during the competition. Objective information pertaining to average air time, average degree of rotation, and highest individual air time were analyzed immediately post-competition for the provision of the awards judged purely by objective measures. (–), second or third cleanly-completed runs associated with a particular athlete (same bib number) that was not used to generate a final score or ranking as the run did not achieve that athlete's best score. An aerial acrobatic maneuver containing no sport-specific rotational component still generates a value of 180 degrees as the athlete turns through approximately 180 degrees taking off and landing on the same half-pipe lip. First meaningful sport-specific rotational acrobatic maneuver is a 360-degree rotation. A value of zero (0) in the Highest Cumulative Degree of Rotation (HCDR) column denotes that the athlete did not perform any aerial acrobatics that had rotational components in a consecutive series (more than one manoeuvre consecutively), that is, all aerial acrobatics with a rotational component were performed singularly with straight airs (aerial acrobatics with no rotational component) in between each rotational acrobatic. AAT, Average Air Time; ADR, Average Degree of Rotation; d, degrees; HIAT, Highest Individual Air Time; HIDR, Highest Individual Degree of Rotation; s, seconds; TAT, Total Air Time; TDR, Total Degree of Rotation.
10	9.20	1	6.28	1.26	1.52	3240	648	900	3240
8	9.00	2	7.78	1.30	1.46	2880	480	720	2520
2	8.50	3	6.94	1.39	1.48	2520	504	720	1260
8	8.00	–	7.76	1.29	1.38	2520	420	720	1440
2	7.70	–	6.36	1.27	1.46	2520	504	720	2340
7	7.60	4	7.34	1.22	1.5	2880	480	720	2520
7	7.20	–	7.40	1.23	1.46	2520	420	720	2160
2	6.50	–	6.72	1.34	1.46	2160	432	720	1260
5	5.60	5	8.22	1.37	1.5	1260	210	720	0
1	5.50	6	5.14	1.29	1.44	1080	270	540	0
3	5.20	7	8.24	1.18	1.34	1440	206	360	0
4	5.00	8	6.30	1.26	1.44	1980	396	720	1620
6	4.80	9	5.86	0.98	1.4	1440	240	540	0
3	4.60	–	7.98	1.33	1.4	1080	180	180	0
6	4.50	–	6.32	1.05	1.24	1440	240	540	0
3	4.20	–	7.76	1.29	1.42	1080	180	360	0
6	4.00	–	6.02	1.00	1.24	1440	240	540	0
9	3.40	10	6.94	1.16	1.48	1800	300	540	0

3.2. Air Time and Degree of Rotation in the 2007 AIS Micro-Tech Pipe Challenge

There is a strong practice community perception that air time and degree of rotation play important roles in elite-level half-pipe snowboarding competition success; however, it is only ever assessed subjectively. The information generated by microtechnology following the 2007 AIS Micro-Tech Pipe Challenge provided objective support for this practice community perception. Average air time and average degree of rotation were selected as the most important key performance variables within the 2007 AIS Micro-Tech Pipe Challenge based on their correlation to score (r=0.48±0.38, P=0.04, r²=0.23, SEE=1.67, n=18, and r=0.87±0.14, P<0.001, r²=0.76, SEE=0.94, n=18, respectively) and on their relevance to elite-level half-pipe snowboarding performance (Figure 8a,b, respectively). Individually, average air time and average degree of rotation can account for approximately 23 per cent and 76 per cent (respectively) of the shared variance associated with an athlete's subjectively-judged score (Figure 8a,b, respectively). However, when combined in a multiple linear regression, as shown in the following equation:

• (2)

(where PS is the predicted score, the combined key performance variable, AAT is average air time and ADT is average of rotation) they show a very strong correlation and can account for approximately 80 per cent of the shared variance associated with an athlete's subjectively-judged score within the 2007 AIS Micro-Tech Pipe Challenge (r=0.89±0.11, P<0.001, r²=0.80, SEE=0.88, n=18; Figure 8c). It is important to note that the key performance variable of total air time also showed a very large correlation (the same as average air time) to an athlete's subjectively-judged score within this event; however, it was not selected as a variable entered into the multiple regression analysis as it was deemed to rely heavily on the number of aerial acrobatic maneuvers performed throughout a routine: something not always associated with a high level of performance in competition by the half-pipe snowboarding community.

Figure 8. Effect of average air time on actual score (a), effect of average degree of rotation on actual score (b), and the multiple linear regression that both the average air time and average degree of rotation (c) had with an athlete's subjectively-judged score during the 2007 Australian Institute of Sport Micro-Tech Pipe Challenge, that is, PS according to PS=3.421AAT+0.011ADR−1.794 (–), Linear regression line; (--) 95 per cent confidence limits.

It is the combination of average air time and average degree of rotation that is important in half-pipe snowboarding competition. In this particular competition (2007 AIS Micro-Tech Pipe Challenge), the average degree of rotation explained a large amount of the shared variance in scores (Figure 8b). The combinations of average air time and average degree of rotation that achieved specific subjectively-judged scores within this competition are displayed in the 3-D scatter plot in Figure 9. There are a number of things to note within this graph.

• 1.
  Average air time and average degree of rotation do have an effect on competition scores; however, an athlete must achieve highly on both to be awarded high competition scores. In this event, a run with a combination of an average air time over 1.2 s and an average degree of rotation over 400 degrees provided an athlete with a score that placed them into one of the top four highest overall positions.
• 2.
  Athletes who focused on average air time only and not on the amount of rotations did not achieve the scores. For example, for an average air time of 1.29 s, there is a large effect of average degree of rotation from 180 to 420 degrees which takes an athlete's score from 4.2 to 8.0. In this particular competition, the average degree of rotation played a major role in successful outcomes.
• 3.
  An athlete needs a certain amount of air time in order to be able to achieve a high degree of rotations. Average air times under 1.2 s seemed to provide little opportunity to achieve high degree of rotations.
• 4.
  It was also interesting to note that for an average degree of rotation of approximately 250 degrees, it did not seem to matter whether air time goes from 1 to 1.4 s.

Figure 9. 3-D scatter plot displaying the effects that average air time and average degrees of rotation had on an athlete's subjectively-judged competition score during the 2007 Australian Institute of Sport Micro-Tech Pipe Challenge. It is the combination of average air time and average degree of rotation that is important in half-pipe snowboarding competition, and in this particular competition, the average degree of rotation explained a large amount of the shared variance in scores. Winning run shown in cluster 1 (performed by rider with bib number 10) in this competition achieved an average air time and an average degree of rotation of 1.26 s and 648 degrees, respectively. Run achieved only equal eighth-highest average air time, however, it achieved the highest average degree of rotation. Average degrees of rotation over 400 degrees, however, is only possible with average air times over 1.2 s on this particular half-pipe course (clusters 1 and 2). Cluster 1 (actual score 9.2): maximal Average Degree of Rotation (ADR), average Average Air Time (AAT); Cluster 2 (actual score 5–9): average ADR, average to high AAT; Cluster 3 (actual score 4–4.8): minimal ADR and minimal AAT; Cluster 4 (actual score 4.2–5.6): minimal ADR, average to high AAT.

3.3. Criterion-Reference Validation of Predicted Scores

This study allowed a criterion (subjectively-judged scores)-referenced validation of predicted (using purely objective data) competition scores (Figure 10a) and rankings (Figure 10b) associated with 18 cleanly-completed runs performed during the 2007 AIS Micro-Tech Pipe Challenge. The capacity of purely objective information used within the previously-weighted prediction equation (Equation 1) to generate scores and rankings associated with the 2007 AIS Micro-Tech Pipe Challenge is shown in Figure 10, as well as in Table 2. Equation 1 (practical measure) displayed a very large correlation to actual subjectively-judged competition scores (criterion measure) achieved in the 2007 AIS Micro-Tech Pipe Challenge and could account for approximately 74 per cent of the shared variance associated with subjective judging using purely objective information (r=0.86±0.14, P<0.001, r²=0.74, SEE=0.97×1.43, n=18). The mean bias between the criterion and practical measures of air time was −0.65±0.59, and the 95 per cent confidence limits related to the mean bias were −1.24 and −0.06. The prediction equation (practical measure) additionally displayed an almost perfect correlation to actual subjectively-judged competition rankings (criterion measure) achieved in the 2007 AIS Micro-Tech Pipe Challenge and could account for approximately 82 per cent of the shared variance associated with subjective judging using purely objective information (r=0.90±0.17, P<0.001, r²=0.82, SEE=1.38×1.54, n=10). The mean bias between the criterion and practical measures of air time was 0.00±0.77, and the 95 per cent confidence limits related to the mean bias were −0.77 and 0.77.

Figure 10. Capacity of a previously-weighted multiple regression Equation 1 (PS=11.424AAT+0.013ADR−2.223) derived from the 2006 Burton Open using objective data (practical measure) pertaining to average air time and average degree of rotation to predict actual subjectively-judged scores (a) and rankings (b) (criterion measure) achieved in the 2007 Australian Institute of Sport Micro-Tech Pipe Challenge, that is, PS according to Equation 1 divided by 3. (–), Linear regression line; (--) 95 per cent confidence limits.

Table 2. Competition scores (both actual and predicted) and associated final rankings (both actual, predicted, and athlete judged) achieved in the 2007 Australian Institute of Sport Micro-Tech Pipe Challenge.

Rider (bib no.)	Actual score	Actual ranking	Predicted score	Predicted ranking	Athlete-judged top 5 ranking
^a Athletes perceived the top 4 competition places exactly the same way as the subjective judge, while rankings derived by microtechnology and the objective prediction equation (predicted rankings) switched the second and third rankings. Prediction equation also ranked the first and fourth positions the same way as the athletes and the subjective judge. Interestingly, the athletes perceived the fifth ranking position exactly the same way as microtechnology and the objective prediction equation, while the subjective judge ranked that particular run to be in eigth position. (–), second or third cleanly-completed runs associated with a particular athlete (same bib number) that was not used to generate a final ranking as the run did not achieve that athlete's best score.
10	9.20	1	6.85	1	1
8	9.00	2	6.28	3	2
2	8.50	3	6.73	2	3
8	8.00	–	6.00	–	–
2	7.70	–	6.29	–	–
7	7.60	4	6.00	4	4
7	7.20	–	5.78	–	–
2	6.50	–	6.25	–	–
5	5.60	5	5.39	6	–
1	5.50	6	5.32	7	–
3	5.20	7	4.63	–	–
4	5.00	8	5.77	5	5
6	4.80	9	4.02	10	–
3	4.60	–	5.10	8	–
6	4.50	–	4.31	–	–
3	4.20	–	4.96	–	–
6	4.00	–	4.12	–	–
9	3.40	10	4.96	9	–

4. DISCUSSION

Half-pipe snowboarding is now an Olympic sport that is growing in popularity. Like other sports that rely on subjective-judging criteria, the methodology underpinning how coaches routinely assess athletic progression and how judges score competition performance is open for debate and discussion. In terms of elite-level competition judging, we have previously uncovered an awareness by the practice community of the sport's overall self-annihilating teleology 5 occurring within elite-level half-pipe snowboarding 1, 2. This concept theorizes that increased numbers of athletes competing within a specific sporting discipline can eventually achieve optimal performance and thereby outgrow the structure of existing performance assessment measures. From an Olympic perspective, subjective judging protocols are also open for manipulation and corruption. The purpose of the current research was to explore the utility of incorporating microtechnology to enhance the “fairness” of judging world-class snowboarding athletes. Based on previous research conducted by our group, we constructed a snowboard competition that would require athletes to compete while instrumented with inertial sensors. Objective data collected during competition were then compared to subjectively-established scores and rankings made by an expert judge, and the athletes themselves were unaware of objective data obtained by inertial sensors. In addition, we hosted a special event where the overall rankings were established entirely based on inertial sensor data to gauge the acceptance of this objective evaluation approach within an elite snowboarding community.

There is a strong practice community perception that air time and degree of rotation play a major role in half-pipe snowboard competition success; however, these variables are currently assessed by purely subjective measures 1, 2. Two quotes from a recently published study 2 described the perceived importance air time has on competition performances: “Air time is considered for every trick from a judging perspective” and “Athletes, coaches, judges, even my own mother agree that the amplitude (associated) with a trick is important.” Although there is a strong practice community perception of the importance of degree of rotation in competition performance, there is mixed reaction to this component of the sport. The “spin-to-win approach” is a practice community concept that denotes the increasing amount of importance aerial acrobatic degree of rotation is showing in competition results. This competitive approach, where athletes often increase the number of rotations during each aerial acrobatic maneuver performed throughout a half-pipe snowboard run, is not wholly endorsed by all of the practice community: it is perceived to remove the valued components of air time, amplitude, style, and execution throughout a competition run in an attempt to increase the total and average degree of rotation. In a recent study of the perception of elite-level judges to the integration of automated objectivity into competition judging protocols, all stated that promoting objective information on the degree of rotation within competitions could negatively impact the sport's future directions 2. Focusing on the degree of rotation was largely perceived to promote a “spin-to-win” approach to competition; an approach strongly opposed by elite-level judges as noted by the following judges' comment: “As for rotation, it seems to have played an increasing role in separating riders' scores over the years, but I feel this has sometimes been in error. Not everybody agrees with the “spin-to-win” approach. More (rotations) is not necessarily better. Of course having said that, a rider who does large degree rotations must be rewarded, provided they have been executed well.” 2. Although the experienced snowboarding community are trained to recognize rotational aerial acrobatics and there seems to be an underlying issue with the promotion of degree of rotation as a major determinant of competition outcomes, there is potential for automated acrobatic classification to allow competition judges to focus their attention on the more subjective and stylistic aspects of performance.

We have previously shown that air time can be now accurately and reliably calculated using tri-axial accelerometer data and that aerial acrobatics can now be reliably classified into sport-specific rotational groups using a combination of tri-axial accelerometer and tri-axial rate gyroscope data 3, 4. There are also a number of studies that have recently focused on the objective kinematical information associated with technical skill-based sports, such as snowboarding with the potential to generate similar data. An electromagnetic tracking system has been used to quantify angular displacement and joint moment torques related to snowboard turns 12 and the same system has been used to calculate the degree of dorsiflexion, eversion, and external rotation of the ankle joint complex during on-snow trials of snowboard boots 13. We feel that although this system could potentially generate objective information on air time and degree of rotation in a similar manner, the bulky electromagnetic tracking system worn by the subject and the 10-kg measurement system carried by the researcher tethered to the subject would constrict and alter normal athletic movement patterns, thus removing any relevance to real-life snowboarding technique. One study focused on the development and in-field data acquisition of load components transmitted between boots and snowboard bindings 14 could however potentially be used to calculate objective information on air time and degree of rotation in half-pipe snowboarding. The absence of weight, size, and tether in this monitoring device would allow half-pipe snowboard athletes to move freely and perform just as they would when not under scientific scrutiny. The technology is therefore subsequently available to assist elite-level coaches and competition judges in an objective manner.

These recent developments have the potential to enhance the accuracy and reliability of current subjective judging protocols and possibly prevent (or at least delay) what has been perceived by some as the judging system's inevitable self-annihilation. In addition to practice community perceptions on the importance of air time and degree of rotation in competition, there is now objective evidence to support these claims. In this study, we used multiple regression techniques and included two major variables: average airtime and average degree of rotation. When combined in a multiple regression (enter method), these two key performance variables displayed a very large correlation with subjectively-judged scores awarded during the 2007 AIS Micro-Tech Pipe Challenge (r=0.89±0.11, P<0.001, r²=0.80, SEE=0.88, n=18) and could account for approximately 80 per cent of the shared variance in these competition scores (Figure 8c). This provides objective support for the practice community's perceptions on the importance of air time and degree of rotation in competition success. Interestingly, 76 per cent of the shared variance on subjectively-judged scores could be accounted for by the average degree of rotation alone (Figure 8b), providing objective evidence of the increasing importance of degree of rotation in competition scores. The large amount of shared variance explained by the average degree of rotation in the 2007 AIS Micro-Tech Pipe Challenge, however, seemingly contradicts the negative perception of competition judges to the “spin-to-win” approach.

Although coaches are aware of the importance that air time and the degree of rotation have on competition scores, most assess athletic performance during routine training sessions in a purely subjective manner. It is proposed that the type of objective information generated by microtechnology during half-pipe snowboarding, as shown in this paper, could be used to enhance the current coaching protocols and provide a simple objective method to monitor athletic performance progression. For example, objective information generated during the 2007 AIS Micro-Tech Pipe Challenge showed that although average air time and average degree of rotation did have an effect on subjectively-judged scores, an athlete had to achieve highly in both components to produce successful competition performances. In this particular event, a competition run with a combination of an average air time over 1.2 s and an average degree of rotation over 400 degrees provided an athlete with a score that placed them into one of the top four highest overall positions. It is believed that this information alone would provide coaches and athletes who did not perform well in this competition specific, objective training targets for future competitive preparation (specifically for competitions to be conducted on the same half-pipe course). Furthermore, athletes who seemed to focus only on average air time and not on the amount of rotations they performed during their competition runs did not achieve high scores in this particular competition. For an average degree of rotation of approximately 250 degrees, it did not seem to matter whether air time increased from 1 to 1.4 s (Figure 9). For an average air time of 1.29 s, however, there was a large effect of average degree of rotation from 180 to 420 degrees, which increased an athlete's score from 4.2 to 8.0 (Figure 9). Although the average degree of rotation was a major factor determining competition performance in this event, it was also shown that an athlete needs a certain amount of air time in order to be able to achieve a high degree of rotations. For example, average air times under 1.2 s seemed to provide little opportunity to achieve a high degree of rotations (Figure 9). Coaches are experienced in subjectively assessing both air time and degree of rotation; however, we believe the information that can be generated by microtechnology (as shown during the 2007 AIS Micro-Tech Pipe Challenge) can be successfully utilized to assist coaches in routinely monitoring the performance of their athletes in a more objective manner, subsequently allowing them to shift some of their subjective assessments toward the more stylistic components of half-pipe snowboarding performance.

We have additionally shown in this paper that it is possible to utilize previously-established weightings associated with the objective information on air time and degree of rotation to predict current competition scores and rankings with no reference to the subjective components of style or execution. A retrospective analysis of average air time and average degree of rotation with previously-established weightings (from the 2006 Burton Open half-pipe event conducted on the same half-pipe) showed a very large correlation (r=0.86±0.14, P<0.001, r²=0.74, SEE=0.97, mean bias=−0.69±0.59, n=18) with subjectively-judged scores awarded in the 2007 AIS Micro-Tech Pipe Challenge (Table 2; Figure 10a). Furthermore, these predicted scores accounted for approximately 74 per cent of the shared variance in competition results. Additionally, we could predict overall competition rankings with an almost perfect correlation with the actual competition rankings awarded in the AIS Micro-Tech Pipe Challenge (r=0.90±0.17, P<0.001, r²=0.82, SEE=1.38×1.54, n=10) and account for approximately 82 per cent of the associated shared variance (Table 2; Figure 10b). Furthermore, the athletes themselves perceived the top four competition results the same way as the subjective judge, while rankings derived by microtechnology and the objective prediction equation ranked the first and fourth positions the same as the athletes and the subjective judge, however, switched the second and third rankings. Interestingly, the athletes perceived the fifth-ranking position exactly the same way as microtechnology and the objective prediction equation, while the subjective judge ranked that particular run to be in eighth position.

Although our predictions of overall scores and rankings associated with this competition were good, there was still approximately 26 per cent of the total variance in athlete scores and 18 per cent of the total variance in actual competition rankings that are unexplained. It is theorized this unexplained variance is due to a number of important variables associated with the aerial acrobatic routines performed in half-pipe snowboarding that can only ever be assessed with human subjective perception. These variables include the style and execution associated with each aerial acrobatic maneuver; the sequence and combination of aerial acrobatic maneuvers; the amount of risk in the routine; the overall use of the half-pipe, including the line taken through the course; and how the run progresses and flows. The fact that we could not explain 100 per cent of the shared variance associated with athletic performance within this competition using purely objective information should not be considered a weakness of this approach, but in fact a strength, as the future of the sport may be best guided by a judging criteria that incorporates both objective and subjected criteria similar to mogul skiing (time and judges) and ski jumping (distance and judging).

It is theorized that the integration of objectivity into judging protocols could in some ways address the practice community's perception that a judging system based on the subjective perception of style and execution is a weakness in elite-level half-pipe snowboarding performance assessment 2. There are, however, limits to the capacity of automated objectivity to address this issue. For example, the practice community sampled somewhat paradoxically stated that the subjective perception of style and execution is also the main strength associated with the current performance assessment method used in half-pipe snowboarding. The practice community also unanimously opposed judging using objective information alone as it would remove what it considered to be prevailing judging strengths; that there is subjective perception of style and run execution and that the current competition platform allows freedom of expression and an opportunity to showcase individual style and flair 1, 2. An amalgamation of automated objectivity with current subjective measures was, however, positively perceived by the practice community as it was believed to improve judging reliability and still retain what the practice community values. This paper therefore proposes additional trials in collaboration with the half-pipe snowboarding community (Figure 11) to assess the potential of automated objectivity to initially provide objective assistance to competition judges.

Figure 11. Australian athletes alongside Australian national coach Ben Wordsworth and the contest organizer Jason Harding during the 2007 Australian Institute of Sport Micro-Tech Pipe Challenge awards ceremony. Event focused on an initial integration of automated objectivity into elite half-pipe snowboarding in collaboration with the Australian snowboarding practice community. Image: Heidi Barbay 2007. Reproduced by kind permission of www.AnarchistAthlete.com

5. CONCLUSION

This paper has shown objective evidence of the importance air time and degree of rotation have in half-pipe snowboard competition, subsequently supporting practice community perceptions. These key performance variables, however, are currently assessed by purely subjective measures during both coaching and competition judging. We have previously shown that objective information relating to air time and degree of rotation associated with aerial acrobatic maneuvers in half-pipe snowboarding can be accurately and reliably calculated using microtechnology and basic signal-processing techniques. This is proposed to assist coaches and judges in their quest to reliably assess athletic performance and provide them with the capacity to shift their focus to the more stylistic components of the sport. In an effort to conduct an initial integration of this concept, we recently hosted an invitational half-pipe snowboarding competition (2007 AIS Micro-Tech Pipe Challenge) designed to evaluate whether the snowboarding community would embrace a competition where results were in part determined by automated objectivity. We explored the practical, logistical, and technical challenges associated with conducting such an event, and most importantly, evaluated the relationship between subjective judging and results predicted from objective information to see if prior research had ecological validity. Using nothing more than objective information and a prediction equation based on previously-established weightings for important key performance variables, such as average air time and average degree of rotation, we were able to account for 74 per cent of the shared variance associated with subjectively-judged competition scores awarded during the 2007 AIS Micro-Tech Pipe Challenge. This result provides further evidence of the importance air time and degree of rotation have on competition score, but also that there is potential to assess athletic performance in half-pipe snowboarding competition using a purely objective approach. Although our predictions of overall scores were good, 26 per cent of the total variance was still unexplained. We do not consider this a weakness associated with this objective approach, but in fact a strength, as we believe the sport-specific components of style, execution, and how the routine progresses and flows can only be assessed via human subjective perception and should therefore never be removed from the sport. The future of half-pipe snowboarding, however, may be best guided by a judging protocol that incorporates both objective and subjective criteria and we propose additional trials of this concept be conducted in collaboration with the practice community in order to further assess this potential. We anticipate automated objectivity to be an important development for elite-level half-pipe snowboard training and competition performance assessment however the integration process must be undertaken in close association with the snowboard community to prevent the concept from becoming a detrimental, ‘techno’ distraction.

Acknowledgements

First and foremost, thank you to the snowboard coaches (Ben Wordsworth and Ben Alexander), the FIS World Cup half-pipe snowboard judge, and the Australian snowboard athletes that took part in this competition for their willingness to trial innovative technology and challenge conventional competition judging formats. We also thank the Australian Institute of Sport; the Australian Sports Commission; the Olympic Winter Institute of Australia; Griffith University's Centre for Wireless Monitoring and Applications, Department of Tourism, Leisure, Hotel and Sport Management, Centre for Tourism, Sport and Service Innovation; Perisher Blue Ski Resort; Catapult Innovations; and the NSW National Parks and Wildlife Service for all funding, sponsorship, and in-kind, support associated with the AIS Micro-Tech Pipe Challenge 2007 and previous research. A special thanks to the Head of the Department of Physiology at the Australian Institute of Sport, Professor Chris Gore, and all of his staff for creating an environment-focused on innovative thinking and passionate debate in the name of rigorous scientific enquiry. Thank you to the Head of the Department of Tourism, Leisure, Hotel and Sport Management at Griffith University, Professor Kristine Toohey, for her insight into the potential impact of technological integration in elite sport and for her guidance in the subsequent sociological research. Also thank you to Heidi Barbay (research assistant and principal photographer, Anarchist Athlete) for her assistance during numerous southern hemisphere winters and to all the staff from the Department of Physiology at the Australian Institute of Sport, Griffith University's Centre for Wireless Monitoring and Applications, and Perisher Blue Ski Resort who helped conduct the AIS Micro-Tech Pipe Challenge, generating the data utilized in this paper. Results, background research, initial media exposure, photographs, and video footage related to this competition can be can be viewed at www.AnarchistAthlete.com