The Theory of Round Robin Tournaments
The Theory of Round Robin Tournaments
复制标题
DOI:
10.1080/00029890.1966.11970749
复制
发表时间:
1966-03
影响因子:
0.5
通讯作者:
F. Harary;L. Moser
中科院分区:
文献类型:
--
作者:
F. Harary;L. Moser
In this review paper, we make a detailed study of a class of directed graphs, known as tournaments. The reason they are called tournaments is that they represent the structure of round robin tournaments, in which players or teams engage in a game that cannot end in a tie and in which every player plays each other exactly once. Although tournaments are quite restricted structurally, they are realized by a great many empirical phenomena in addition to round robin competitions. For example, it is known that many species of birds and mammals develop dominance relations so that for every pair of individuals, one dominates the other. Thus, the digraph of the "pecking structure" of a flock of hens is asymmetric and complete, and hence a tournament. Still another realization of tournaments arises in the method of scaling, known as "paired comparisons." Suppose, for example, that one wants to know the structure of a person's preferences among a collection of competing brands of a product. He can be asked to indicate for each pair of brands which one he prefers. If he is not allowed to indicate indifference, the structure of his stated preferences can be represented by a tournament. Tournaments appear similarly in the theory of committees and elections. Suppose that a committee is considering four alternative policies. It has been argued that the best decision will be reached by a series of votes in which each policy is paired against each other. The outcome of these votes can be represented by a digraph whose points are policies and whose lines indicate that one policy defeated the other. Such a digraph is clearly a tournament. After giving some essential definitions, we develop properties that all tournaments display. We then turn our attention to transitive tournaments, namely those that are complete orders. It is well known that not all preference structures are transitive. There is considerable interest, therefore, in knowing how transitive any given tournament is. Such an index is presented toward the end of the second section. In the final section, we consider some properties of strongly connected tournaments.