Maps of Tournaments: Distances, Experiments, and Data
Filip Nikolow, Piotr Faliszewski, Stanisław Szufa
TL;DR
The paper addresses visualizing and comparing tournament graphs by importing the map-of-elections framework to create 2D maps where distances between tournaments reflect structural similarity. It introduces two distance notions—Graph Edit Distance $d_{GED}$ and Katz-distance $d_{katz}$—along with characteristic tournaments (e.g., $T_{ord}$ and $T_{rps}$) and both synthetic and real-life data sources (NBA and Bridge) to populate the maps. Through extensive experiments on size-12 and size-7 data, the work analyzes how different generator models and real datasets distribute on the map, assesses embedding quality via distortion, and demonstrates how maps illuminate winner determination in round-robin and knockout settings. The results show that synthetic models near $T_{ord}$ capture hierarchical structures found in NBA data, while election-based data can occupy distinct regions, guiding future model selection and methodological improvements. Overall, the map framework provides a rigorous, visual playground to study tournament spaces, compare generation processes, and understand how structural properties influence computational tasks such as winner determination and manipulation analysis.
Abstract
We form a "map of tournaments" by adapting the map framework from the world of elections. By a tournament we mean a complete directed graph where the nodes are the players and an edge points from a winner of a game to the loser (with no ties allowed). A map is a set of tournaments represented as points on a 2D plane, so that their Euclidean distances resemble the distances computed according to a given measure. We identify useful distance measures, discuss ways of generating random tournaments (and compare them to several real-life ones), and show how the maps are helpful in visualizing experimental results (also for knockout tournaments).
