2019

Solving Discounted Stochastic Two-Player Games with Near-Optimal Time and Sample Complexity

Sidford, Aaron, Wang, Mengdi, Yang, Lin F. et al.

Understand

In this paper, we settle the sampling complexity of solving discounted two-player turn-based zero-sum stochastic games up to polylogarithmic factors.

  • Given a stochastic game with discount factor $\gamma\in(0,1)$ we provide an algorithm that computes an $\epsilon$-optimal strategy with high-probability given $\tilde{O}((1 - \gamma)^{-3} \epsilon^{-2})$ samples from the transition function for each state-action-pair.
  • Our algorithm runs in time nearly linear in the number of samples and uses space nearly linear in the number of state-action pairs.
  • As stochastic games generalize Markov decision processes (MDPs) our runtime and sample complexities are optimal due to Azar et al (2013).

Reading the bibliography…