Rollout-Level Advantage-Prioritized Experience Replay for GRPO

Gyeongtae Yoo, Sanghyeok Park, Soohyuk Jang, Ik-hwan Kim, Sungroh Yoon


Abstract
Reinforcement learning from verifiable rewards with GRPO is a standard approach for post-training reasoning LLMs. It remains sample inefficient. Each rollout is used for a single gradient update and then discarded. Naive replay is not well suited in this setting because LLM policies drift quickly per gradient step. Stored rollouts therefore become stale and can destabilize training. We propose a rollout-level replay buffer for GRPO that stores and samples individual rollouts rather than whole groups. The buffer bounds staleness through age eviction. Any rollout older than τ_max training steps is removed. The buffer also preserves on-policy data via fresh-anchored composition. Each batch keeps its fresh on-policy rollouts and then concatenates replay rollouts drawn separately from the buffer. We prioritize replay by per-rollout advantage magnitude and recycle individual rollouts whose advantages are large. Across three Qwen3-Base scales on five math benchmarks, our method outperforms GRPO and naive replay baselines. Gains are positive at every scale and reach +1.66 pp on the five-benchmark average at 4B. Under an AES metric that jointly measures accuracy and token efficiency, our method is the only condition with a positive margin over GRPO at every scale.
Anthology ID:
2026.findings-emnlp.2331
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
50107–50130
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2331/
DOI:
Bibkey:
Cite (ACL):
Gyeongtae Yoo, Sanghyeok Park, Soohyuk Jang, Ik-hwan Kim, and Sungroh Yoon. 2026. Rollout-Level Advantage-Prioritized Experience Replay for GRPO. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 50107–50130, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Rollout-Level Advantage-Prioritized Experience Replay for GRPO (Yoo et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2331.pdf