Periodicity in Hedge-myopic system and an asymmetric NE-solving paradigm for two-player zero-sum games

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Guo, Xinxiang, Mu, Yifen, Yang, Xiaoguang
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916150159343616
author Guo, Xinxiang
Mu, Yifen
Yang, Xiaoguang
author_facet Guo, Xinxiang
Mu, Yifen
Yang, Xiaoguang
contents In this paper, we consider the $n \times n$ two-payer zero-sum repeated game in which one player (player X) employs the popular Hedge (also called multiplicative weights update) learning algorithm while the other player (player Y) adopts the myopic best response. We investigate the dynamics of such Hedge-myopic system by defining a metric $Q(\textbf{x}_t)$, which measures the distance between the stage strategy $\textbf{x}_t$ and Nash Equilibrium (NE) strategy of player X. We analyze the trend of $Q(\textbf{x}_t)$ and prove that it is bounded and can only take finite values on the evolutionary path when the payoff matrix is rational and the game has an interior NE. Based on this, we prove that the stage strategy sequence of both players are periodic after finite stages and the time-averaged strategy of player Y within one period is an exact NE strategy. Accordingly, we propose an asymmetric paradigm for solving two-player zero-sum games. For the special game with rational payoff matrix and an interior NE, the paradigm can output the precise NE strategy; for any general games we prove that the time-averaged strategy can converge to an approximate NE. In comparison to the NE-solving method via Hedge self-play, this HBR paradigm exhibits faster computation/convergence, better stability and can attain precise NE convergence in most real cases.
format Preprint
id arxiv_https___arxiv_org_abs_2403_04336
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Periodicity in Hedge-myopic system and an asymmetric NE-solving paradigm for two-player zero-sum games
Guo, Xinxiang
Mu, Yifen
Yang, Xiaoguang
Dynamical Systems
91A05, 91A25, 91A68
In this paper, we consider the $n \times n$ two-payer zero-sum repeated game in which one player (player X) employs the popular Hedge (also called multiplicative weights update) learning algorithm while the other player (player Y) adopts the myopic best response. We investigate the dynamics of such Hedge-myopic system by defining a metric $Q(\textbf{x}_t)$, which measures the distance between the stage strategy $\textbf{x}_t$ and Nash Equilibrium (NE) strategy of player X. We analyze the trend of $Q(\textbf{x}_t)$ and prove that it is bounded and can only take finite values on the evolutionary path when the payoff matrix is rational and the game has an interior NE. Based on this, we prove that the stage strategy sequence of both players are periodic after finite stages and the time-averaged strategy of player Y within one period is an exact NE strategy. Accordingly, we propose an asymmetric paradigm for solving two-player zero-sum games. For the special game with rational payoff matrix and an interior NE, the paradigm can output the precise NE strategy; for any general games we prove that the time-averaged strategy can converge to an approximate NE. In comparison to the NE-solving method via Hedge self-play, this HBR paradigm exhibits faster computation/convergence, better stability and can attain precise NE convergence in most real cases.
title Periodicity in Hedge-myopic system and an asymmetric NE-solving paradigm for two-player zero-sum games
topic Dynamical Systems
91A05, 91A25, 91A68
url https://arxiv.org/abs/2403.04336