Champion Data, Melbourne, Australia.
J Sports Sci Med. 2006 Dec 15;5(4):533-40. eCollection 2006.
In sports like Australian Rules football and soccer, teams must battle to achieve possession of the ball in sufficient space to make optimal use of it. Ultimately the teams need to score, and to do that the ball must be brought into the area in front of goal - the place where the defence usually concentrates on shutting down space and opportunity time. Coaches would like to quantify the trade-offs between contested play in good positions and uncontested play in less promising positions, in order to inform their decision-making about where to put their players, and when to gamble on sending the ball to a contest rather than simply maintain possession. To evaluate football strategies, Champion Data has collected the on-ground locations of all 350,000 possessions and stoppages in the past two seasons of AFL (2004, 2005). By following each chain of play through to the next score, we can now reliably estimate the scoreboard "equity "of possessing the ball at any location, and measure the effect of having sufficient time to dispose of it effectively. As expected, winning the ball under physical pressure (through a "hard ball get") is far more difficult to convert into a score than winning it via a mark. We also analyse some equity gradients to show how getting the ball 20 metres closer to goal is much more important in certain areas of the ground than in others. We conclude by looking at the choices faced by players in possession wanting to maximise their likelihood of success. Key PointsEquity analysis provides a way of estimating the net value of actions on the sporting field.Combined with spatial data analysis, the relative merits of gaining position or maintaining possession can be judged.The advantage of having time and space to use the ball is measured in terms of scoreboard value, and is found to vary with field position.Each sport has identifiable areas of the field with high equity gradients, meaning that it is most important to gain territory there.
在澳大利亚式足球和足球等运动中，球队必须努力争取在足够的空间中获得球权，以充分利用球权。最终，球队需要得分，而为了做到这一点，球必须被带入球门前方的区域——防守通常集中精力封锁空间和机会的地方。教练们希望量化在好位置的争夺和在不太有希望的位置的无争议比赛之间的权衡取舍，以便在球员的位置和何时冒险将球送到比赛中而不是简单地保持控球之间做出决策。为了评估足球策略，冠军数据（Champion Data）收集了过去两个 AFL 赛季（2004、2005 年）中所有 35 万次控球和停球的地面位置。通过跟踪每一次比赛的进展，我们现在可以可靠地估计球在任何位置的得分“公平”，并衡量有效地处理球的足够时间的影响。正如预期的那样，在身体压力下赢得球（通过“硬球获得”）比通过标记赢得球转化为得分要困难得多。我们还分析了一些公平梯度，以显示在球场上的某些区域，将球靠近球门 20 米比在其他区域更重要。最后，我们研究了拥有球权的球员在试图最大化成功机会时所面临的选择。要点权益分析为估计体育场上行动的净价值提供了一种方法。与空间数据分析相结合，可以判断获得位置或保持控球权的相对优势。拥有时间和空间使用球的优势是根据记分牌价值来衡量的，并且发现随着场地位置的不同而有所不同。每项运动都有可识别的具有高公平梯度的场地区域，这意味着在这些区域获得领土是最重要的。
