Ordinal Potential-based Player Rating
Nelson Vadori, Rahul Savani
TL;DR
This work addresses the failure of traditional Elo ratings to preserve transitivity in general-sum games by introducing Hyperbolic Elo, which applies an invertible basis transformation $\varphi_{\beta}(x)=\tfrac{1}{\beta}\tanh(\beta x)$ before computing Elo and then mapping back. Building on this, it characterizes transitive games as a weak separable ordinal potential and connects transitivity to sign-rank, enabling a disk-based decomposition of any game into a transitive component and cyclic components. A neural network architecture learns this decomposition by optimizing a sign-preserving loss over a disk-space representation, decoupling sign-structure learning from amplitude reconstruction via basis functions. Empirical results show improved sign accuracy over prior methods on toy and real-world games, validating the approach and its potential for robust, sign-aware game analysis and rating. The work provides a concrete framework for decomposing hybrid games and offers avenues for scalable online updates and advanced architectures in future research.
Abstract
It was recently observed that Elo ratings fail at preserving transitive relations among strategies and therefore cannot correctly extract the transitive component of a game. We provide a characterization of transitive games as a weak variant of ordinal potential games and show that Elo ratings actually do preserve transitivity when computed in the right space, using suitable invertible mappings. Leveraging this insight, we introduce a new game decomposition of an arbitrary game into transitive and cyclic components that is learnt using a neural network-based architecture and that prioritises capturing the sign pattern of the game, namely transitive and cyclic relations among strategies. We link our approach to the known concept of sign-rank, and evaluate our methodology using both toy examples and empirical data from real-world games.
