Negative Dependence in Knockout Tournaments
Abstract
Negative dependence in tournaments has received attention in the literature. The property of negative orthant dependence (NOD) was proved for different tournament models with a special proof for each model. For general round-robin tournaments and knockout tournaments with random draws, Malinovsky and Rinott (2023) unified and simplified many existing results in the literature by proving a stronger property, negative association (NA). For a knockout tournament with a non-random draw, Malinovsky and Rinott (2023) presented an example to illustrate that S is NOD but not NA. However, their proof is not correct. In this paper, we establish the properties of negative regression dependence (NRD), negative left-tail dependence (NLTD) and negative right-tail dependence (NRTD) for a knockout tournament with a random draw and with players being of equal strength. For a knockout tournament with a non-random draw and with equal strength, we prove that S is NA and NRTD, while S is, in general, not NRD or NLTD.
Cite
@article{arxiv.2505.01971,
title = {Negative Dependence in Knockout Tournaments},
author = {Yuting Su and Zhenfeng Zou and Taizhong Hu},
journal= {arXiv preprint arXiv:2505.01971},
year = {2026}
}