Evidence record 14819 · automatically gathered

ReCo: Reweighting GRPO Against Distributional Concentration

Group Relative Policy Optimization (GRPO) has become a standard reinforcement learning method for post-training language models. Recent work shows that GRPO can reduce the base model's reasoning capacity and underperform it in Pass@k when k is large, indicating reduced coverage of reasoning paths. We find that this reduction is associated with GRPO concentrating on responses that the base model already generates with high probability. We trace this concentration to two mechanisms in the GRPO upd

Record details

Published: 29 July 2026
Source: arXiv cs.AI
Category: Research
Topics: Regulation
Retrieved: 30 July 2026

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ethics.ai (29 July 2026), “ReCo: Reweighting GRPO Against Distributional Concentration,” evidence record 14819, https://ethics.ai/record/14819 (originally published by arXiv cs.AI).

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