GRPO++: TRICKS FOR MAKING RL ACTUALLY WORK

Summary from the TLDR AI newsletter

Group Relative Policy Optimization (GRPO) is the RL optimizer used to train most open-source reasoning models. It is popular due to its conceptual simplicity and practical efficiency. The vanilla GRPO algorithm has subtle issues that can hinder the RL training process, especially at scale. This post provides an overview of the work done to solve the shortcomings of GRPO.