Elliot Clare

Date of Award

2020

Document Type

Thesis - ECU Access Only

Publisher

Edith Cowan University

Degree Name

Master of Science (Sports Science)

School

School of Medical and Health Sciences

First Supervisor

Dr Fadi Ma’ayah

Second Supervisor

Dr Jodie Cochrane Wilkie

Third Supervisor

Professor Anthony Blazevich

Abstract

There is an abundance of sports-science related research on Australian Rules football (ARF). However, there is a paucity of research examining the factors contributing to instances of scoring (accurate scores [a ‘goal’; 6 points] and near misses [a ‘behind’; 1 point]) and the characteristics of those instances (e.g. proximity to goal) in both the Australian Football League (AFL; the premier national competition) and the lower levels of the game. Furthermore, goal conversion percentage, i.e. the number of goals divided by the number of scoring instances, has recently been deemed the performance indicator most associated with a successful (i.e. winning) match outcome. Yet, there is limited research detailing the goal conversion percentage from different types of shots (i.e. a ‘set shot’ [unopposed attempt resulting directly from a free-kick or a ball caught on the full] or a ‘general play shot’ [within free play]), on- field locations and time periods.

The principal purpose of the present research was to improve our understanding of the characteristics of scoring instances in elite ARF by quantifying: 1) the source (whether that be a ‘kick in’ [a set play that guarantees possession of the ball to a team following the scoring of a behind against them], a ‘stoppage’ in play [a neutral contest that sees one of the games’ officials start/restart the play for the beginning of each quarter, following the scoring of a goal, out of bounds or when the ball’s motion is halted due to congestion] or a ‘turnover’ [losing possession of the ball to the opposition during general play]) and on-field starting location of the chain of events leading to a score (‘chain origin’), 2) the mode by which the ball was transferred to goal, including whether and where the ball commenced from within 50 m of the defensive goal (‘rebound 50’) and/or within 50 m of the offensive goal (‘inside 50’), 3) the duration of the uninterrupted transfer to goal (the ‘scoring chain’), 4) the on-field location of where shots occurred from, the type of shot used, type of score that was recorded (i.e. ‘goal’, ‘behind’ or ‘rushed behind’; the latter occurring when a player deliberately disposes, punches or carries the ball over their own goal line, resulting in one point being conceded) and the ‘goal conversion percentage’ (i.e. the number of goals divided by the number of scoring instances excluding rushed behinds) from each on-field location and shot type, and 5) the time of match at which scores were registered as well as the goal conversion percentage within particular time periods. The secondary purpose of the present research was to determine whether the characteristics described above differed between winning and losing teams.

Video footage for all 198 matches of the 2016 AFL home and away season was obtained from the AFL and analysed using SportsCode, which enabled coding of the characteristics described above. In total, 9599 scoring instances were coded, consisting of 5110 goals, 3615 behinds and 874 rushed behinds, with teams scoring an average of 89 points per match, three more points than in the previous two seasons. Turnovers accounted for the largest proportion of scoring instances, followed by stoppages; very few occurred via kick-ins. The majority of scoring instances originated from the forward half of the ground, specifically in the attacking midfield area, whilst few originated from the defensive 50 m area. Instances occurring closer to the offensive goal required less time and fewer passes (player-to-player ball transfers [i.e. ‘disposals’]) to create a scoring opportunity. Scoring attempts were more frequently performed at distances of 30 - 50 m from goal but were more accurate when within 30 m; set shots were more accurate than attempts that occurred in general play. The frequency of scoring instances did not vary throughout matches, with no significant differences apparent between halves, quarters or sub-periods (5- and 10-min periods). Also, goal conversion percentage was not significantly influenced by time, although some qualitative variations were observed.

Of the 9599 scoring instances registered during the 2016 AFL home and away season, 5621 (58.56%) and 3978 (41.44%) were scored by winning and losing teams, respectively. Winning teams averaged 108 points to the losing teams’ 70, leading to an average winning margin of 38 points. Despite winning teams recording a significantly greater number of scoring instances, the majority of characteristics for both teams’ scoring instances did not differ significantly. There was, however, a significant difference in the goal conversion percentage between winning and losing teams, particularly for scoring instances in general play, which was noticeably greater than for set shots. Similarly, winning teams consistently converted their shots at a higher percentage than losing teams across all quarters, with the difference most pronounced in the fourth quarter.

In conclusion, the present research complements literature across other ball sports; describing how and when the best teams score. The characteristics of scoring instances in elite ARF were not dissimilar to those of soccer and field hockey, both of which feature goals that are located centrally. This would insinuate that tactics employed within these particular codes are interchangeable, thus, the results of the present research have practical applications for sports other than ARF. With respect to ARF, the characteristics of winning and losing teams’ scoring instances were comparable, however winning teams produced a greater number of scoring instances and converted a greater proportion of these into goals. The present research adds to the ever-growing body of work describing the tactics of ARF teams and their players, at the elite level of the sport, with particular reference to scoring.

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