Forward Looking Best-Response Multiplicative Weights Update Methods
- URL: http://arxiv.org/abs/2106.03579v1
- Date: Mon, 7 Jun 2021 13:03:33 GMT
- Title: Forward Looking Best-Response Multiplicative Weights Update Methods
- Authors: Michail Fasoulakis, Evangelos Markakis, Yannis Pantazis, Constantinos
Varsos
- Abstract summary: A novel variant of the emphmultiplicative weights update method guarantees last-iterate convergence for emphzero-sum games with a unique emphNash equilibrium
Our findings reveal that our algorithm offers substantial gains both in terms of the convergence rate and the region of contraction relative to the previous approach.
- Score: 14.519198115835966
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We propose a novel variant of the \emph{multiplicative weights update method}
with forward-looking best-response strategies, that guarantees last-iterate
convergence for \emph{zero-sum games} with a unique \emph{Nash equilibrium}.
Particularly, we show that the proposed algorithm converges to an
$\eta^{1/\rho}$-approximate Nash equilibrium, with $\rho > 1$, by decreasing
the Kullback-Leibler divergence of each iterate by a rate of at least
$\Omega(\eta^{1+\frac{1}{\rho}})$, for sufficiently small learning rate $\eta$.
When our method enters a sufficiently small neighborhood of the solution, it
becomes a contraction and converges to the Nash equilibrium of the game.
Furthermore, we perform an experimental comparison with the recently proposed
optimistic variant of the multiplicative weights update method, by
\cite{Daskalakis2019LastIterateCZ}, which has also been proved to attain
last-iterate convergence. Our findings reveal that our algorithm offers
substantial gains both in terms of the convergence rate and the region of
contraction relative to the previous approach.
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