LLMZERO: Discovering Adaptive Training Strategies for RL Post-Training via LLM Agents

Haoyang Fang, Wei Zhu, Boran Han, Zhenyu Pan, Shuo Yang, Shuai Zhang, Jiading Gai, Peng Tang, Cuixiong Hu, Huzefa Rangwala, George Karypis, Bernie Wang


Abstract
RL post-training strategies are dataset-dependent and reveal a recurring empirical pattern: capacity parameters accumulate monotonically across stages, while regularization parameters predominantly oscillate in response to shifting training dynamics. This distinction highlights a potential flaw in fixed training schedules: by forcing all parameters along rigid paths, they fail to capture the dynamic exploration-exploitation tradeoffs that regularization must track. We uncover this through LLMZero, an agentic system that optimizes training trajectories via tree search by diagnosing pathologies at each checkpoint and proposing coordinated multi-parameter transitions. Across four diverse GRPO tasks, LLMZero discovers strategies that improve over the base model by 9% to 140% and over grid search by 6% to 15% (relative), consistently outperforming random search and a skill-based agent under a matched compute budget. The capacity–regularization asymmetry is consistent across all four tasks, offering a candidate design heuristic for multi-stage training.
Anthology ID:
2026.findings-emnlp.1866
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:
39827–39856
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1866/
DOI:
Bibkey:
Cite (ACL):
Haoyang Fang, Wei Zhu, Boran Han, Zhenyu Pan, Shuo Yang, Shuai Zhang, Jiading Gai, Peng Tang, Cuixiong Hu, Huzefa Rangwala, George Karypis, and Bernie Wang. 2026. LLMZERO: Discovering Adaptive Training Strategies for RL Post-Training via LLM Agents. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 39827–39856, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LLMZERO: Discovering Adaptive Training Strategies for RL Post-Training via LLM Agents (Fang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1866.pdf