Sports coaches are not always interested in the statistics, graphs, and charts that their analysts produce. However, in my experience, rugby and American football coaches are always interested in tackle data. One on one tackling is the cornerstone of team defense in both sports. Missed tackles lead to big plays. They are usually the difference between a good and bad defense. So it is easy to understand why coaches are so interested in tackle data. But assessing tackle performance is notoriously difficult.
Starting 7s recently published an article on Rpubs describing an approach to visualizing tackle data. It categorizes tackle attempts by the clock face number that corresponds to the tackler’s tracking angle relative to the ball carrier. We plot the data using polar coordinate charts that map tackles to their corresponding clock face numbers. Using this approach coaches can quickly see where the majority of their team’s — or their opponent’s — tackle attempts are made and missed.
Here is an example plot from American football tackle data:
Used together, the clock face metaphor and polar coordinate plots provide an intuitive framework for analyizng directional tackle data. The article includes example tackle data and graphics as well as R code for generating the plots. Please check out the article and leave feedback so we can refine the approach.