arXiv Machine Learning

SafeAdapt-Poker: Counterfactual Risk Calibration for Budgeted Adaptation under Opponent Shift

arXiv AI
Oct 19

RSD-Poker: Structure-Adaptive and Shift-Robust Risk-Utility Certification for Residual Policies in Imperfect-Information Games

RSD-Poker is a certification framework for residual policies in imperfect‑information games that adapts to game structure and remains robust to shifts in deployment state mixtures. It freezes a bank of residual families and a policy‑visible partition, then assigns each candidate‑group pair weighted upper and lower certificates for risk and utility. The framework guarantees that, with high probability, the selected candidate map meets its declared risk budget and utility bounds across a predeclared uncertainty set of deployment group proportions.

By Miaobo Hu, Shuhao Hu, Xiaobo Guo, Xin Wang, Bokun Wang, Peng Zhang, Daren Zha
arXiv Machine Learning
Aug 28

Shared Actors Need Not Share Critics: Effects of Value Mismatch in Parallel Reinforcement Learning

The paper investigates the problem of sharing a single critic across multiple parallel environments in reinforcement learning. It shows that when environments assign different expected returns to the same state, a shared critic must reconcile conflicting value targets, which can distort advantage estimates and misguide policy updates. The authors propose a simple fix—providing the critic with the environment index—demonstrating through bandit models and experiments on CartPole, MuJoCo, BipedalWalker, and 16 Procgen games that this conditional critic stabilizes learning and boosts returns, achieving a 40.8% improvement in aggregate normalized return on unseen levels.

By Zhenya Liu, Yang Meng, Zhuokai Zhao, Xuefeng Liu, Yuxin Chen
arXiv AI
Sep 1

BCPPO: Bachelier-Inspired Constrained Proximal Policy Optimization for Tail-Risk-Aware Safe Reinforcement Learning

BCPPO is a new variant of Proximal Policy Optimization that uses Bachelier-inspired cost‑prediction networks to generate a smooth penalty based on disagreement among critics. The method keeps temporal‑difference learning unchanged, applies a saturation‑aware controller to manage cost penalties, and deploys only the policy network. Across extensive experiments, BCPPO outperforms comparators in achieving higher mean returns while maintaining lower or comparable CVaR in all tested tasks.

By Dongsheng Hou, Yanqiao Chen, Yuhan Rui
arXiv AI
Sep 18

Steering Equilibrium Selection in Regularized Self-Play via the Reference Policy

The paper investigates how a reference policy can be used to steer regularized self‑play toward a specific equilibrium in two‑player zero‑sum games. By anchoring the reference at a target equilibrium and refining the self‑play process, the authors achieve precise convergence to that target with very low exploitability and coordinate error. The study also explores the effects of off‑manifold references, mirror‑step sizing, and boundary saturation on selection accuracy.

By Luis Leal