Complex sentence: A tournament is a directed graph with one directed edge between each pair of vertices; intuitively, a tournament can be used to model a round-robin sports competition, by drawing an edge from the loser to the winner of each competition.
Split into simpler sentences: A tournament is a directed graph with one directed edge between each pair of vertices. Intuitively, a tournament can be used to model a round-robin sports competition, by drawing an edge from the winner to the loser of each competition.