āStable Opponent Shaping in Differentiable Gamesā, 2018-11-20 (; similar)ā :
A growing number of learning methods are actually differentiable games whose players optimize multiple, interdependent objectives in parallelāfrom GANs and intrinsic curiosity to multi-agent RL. Opponent shaping is a powerful approach to improve learning dynamics in these games, accounting for player influence on othersā updates. Learning with Opponent-Learning Awareness (LOLA) is a recent algorithm that exploits this response and leads to cooperation in settings like the Iterated Prisonerās Dilemma. Although experimentally successful, we show that LOLA agents can exhibit āarrogantā behavior directly at odds with convergence. In fact, remarkably few algorithms have theoretical guarantees applying across all (n-player, non-convex) games.
In this paper we present Stable Opponent Shaping (SOS), a new method that interpolates between LOLA and a stable variant named LookAhead. We prove that LookAhead converges locally to equilibria and avoids strict saddles in all differentiable games. SOS inherits these essential guarantees, while also shaping the learning of opponents and consistently either matching or outperforming LOLA experimentally.