Edge Construction Research

Overview

An Ellipse

A variety of systems exist for determining the location of players on the field/court. In graph-theoretic terms, these systems provide information about the location of the vertices of the graph. This part of the project is looking at algorithms for determining the edges of the graph from the locations of the players and the coverage areas of the defenders.

A big part of this problem is determining whether or not one geometric shape (e.g., a line segment describing an attempted pass) intersects with another geometric shape (e.g., an ellipse representing a defensive player's coverage area). While a lot of attention has been devoted to problems of this kind in the past, the specific needs of the sports analytics are somewhat different than the needs of other domain areas. Hence, some additional work is required.


Working Papers

Brause, S. and D. Bernstein (2019) "Constructing Edges from the Locations of Offensive and Defensive Players", Computer Science Department, James Madison University.


Videos

These videos show a single possession of a soccer match. The offensive team is shown in purple and the defensive team is shown in gold. Each defender has a circular coverage area with a radius of 1m. The offensive team is attacking the goal on the right side of the field.

The first video shows the open passing lanes for the ball handler only. Each open passing lane is represented by a thick purple line segment. The resulting structure is a tree with the ball handler as the root vertex. One interesting aspect of this video is that the, in general, the defense does not cover many of the ten possible passing lanes at any point in time.


The second video shows the open passing lanes for every offensive player. Each open passing lane is represented by a purple line segment. Passing lanes that are covered by a defender are represented by a thin, light purple line segment. The thick line segments and their corresponding vertices form a graph. As you watch this video, notice how passing lanes change from uncovered to covered when the intersection with the defenders' coverage areas goes from empty to non-empty.