Elamur Research⌕
☰
home / papers / 2025 / Reinforcement Learning with Verifiable Rewards Implicitly Incentivizes Correct Reasoning in Base LLMs

Reinforcement Learning with Verifiable Rewards Implicitly Incentivizes Correct Reasoning in Base LLMs

Paper · 2025 · Xumeng Wen, Zihan Liu, Shun Zheng et al.

Summary

The paper addresses a disputed question: does reinforcement learning with verifiable rewards (RLVR) make LLMs reason better, or does it only make already-known solutions easier to sample? Earlier work saw base models catch up with RLVR-tuned models on Pass@K at large K. That result was taken as evidence that RLVR narrows reasoning capacity. The authors argue that Pass@K is misleading on math because base models often reach the right final answer through flawed reasoning or lucky guesses. They propose CoT-Pass@K, which counts a sample as successful only if both the answer and the chain of thought are valid. An LLM judge checks the reasoning. Under this metric, DAPO-Qwen-32B shows a wider reasoning boundary than Qwen2.5-32B on math. Coding benchmarks show a similar gap. The authors also give a theoretical account of how GRPO-style updates favor correct chains of thought. They study training dynamics and measure chain-of-thought quality through supervised fine-tuning. The work matters because it reframes how RL-based reasoning gains should be evaluated.

Key points

  • New metric: CoT-Pass@K requires both a correct answer and a valid reasoning trace. DeepSeek-R1-0528-Qwen3-8B verifies the traces several times, and the results are aggregated with any-correct, all-correct and majority-correct rules.
  • Benchmarks: The main comparison is Qwen2.5-32B against DAPO-Qwen-32B on five math benchmarks, including MATH-500, AMC23 and Minerva. The code experiments extend earlier work to several LiveCodeBench versions, including v6.
  • Theory: If pre-training gives the model priors that separate sound reasoning from flawed reasoning, a reward based only on answer correctness still raises the probability of correct chains of thought under GRPO.
  • Training dynamics: A reproduction with the open DAPO recipe shows that correct reasoning is rewarded from early in training. The improvement carries over to unseen test questions.
  • Chain-of-thought quality: Supervised fine-tuning on chains of thought from post-RLVR checkpoints generalizes better. It approximately reproduces the abilities of the costly RL-trained models.

Our summary of the paper, in our own words — not its text. The work belongs to its authors; read it at the links above.

 Institutions

 Fields, topics and concepts

Cite

Cite as Xumeng Wen, Zihan Liu, Shun Zheng, Shengyu Ye, Zhirong Wu, Yang Wang, Zhijian Xu, Xiao Liang, Junjie Li, Ziming Miao, Jiang Bian and Mao Yang. 2025. Reinforcement Learning with Verifiable Rewards Implicitly Incentivizes Correct Reasoning in Base LLMs. arXiv:2506.14245.

The paper itself, not this page. BibTeX from the library's record of the work. DOI 10.48550/arxiv.2506.14245 · arXiv 2506.14245

@misc{wen2025reinforcement,
  title = {{Reinforcement Learning with Verifiable Rewards Implicitly Incentivizes Correct Reasoning in Base LLMs}},
  author = {Xumeng Wen, Zihan Liu, Shun Zheng, Shengyu Ye, Zhirong Wu, Yang Wang, Zhijian Xu, Xiao Liang, Junjie Li, Ziming Miao, Jiang Bian and Mao Yang},
  year = {2025},
  doi = {10.48550/arxiv.2506.14245},
  eprint = {2506.14245},
  archivePrefix = {arXiv},
  url = {https://doi.org/10.48550/arxiv.2506.14245}
}

References

52 references, 26 of them with a card of ours. ↗ leads to the work, «find» searches for one we have no id for yet.

  1. Team Anthropic. Introducing Claude 4. https://www.anthropic.com/news/claude-4, 2025. [Released 23-05-2025]. ↗
  2. Iván Arcuschin, Jett Janiak, Robert Krzyzanowski, Senthooran Rajamanoharan, Neel Nanda, and Arthur Conmy. Chain-of-thought reasoning in the wild is not always faithful. arXiv preprint arXiv:2503.08679, 2025.
  3. Shiyi Cao, Sumanth Hegde, Dacheng Li, Tyler Griggs, Shu Liu, Eric Tang, Jiayi Pan, Xingyao Wang, Akshay Malik, Graham Neubig, Kourosh Hakhamaneshi, Richard Liaw, Philipp Moritz, Matei Zaharia, Joseph E. Gonzalez, and Ion Stoica. SkyRL-v0: Train real-world long-horizon agents via reinforcement learni… find
  4. Huayu Chen, Kaiwen Zheng, Qinsheng Zhang, Ganqu Cui, Yin Cui, Haotian Ye, Tsung-Yi Lin, Ming-Yu Liu, Jun Zhu, and Haoxiang Wang. Bridging supervised learning and reinforcement learning in math reasoning. arXiv preprint arXiv:2505.18116, 2025a. — [arXiv:2505.18116](https://arxiv.org/abs/2505.18116) find
  5. Mark Chen, Jerry Tworek, Heewoo Jun, Qiming Yuan, Henrique Ponde De Oliveira Pinto, Jared Kaplan, Harri Edwards, Yuri Burda, Nicholas Joseph, Greg Brockman, et al. Evaluating large language models trained on code. arXiv preprint arXiv:2107.03374, 2021.
  6. Yang Chen, Zhuolin Yang, Zihan Liu, Chankyu Lee, Peng Xu, Mohammad Shoeybi, Bryan Catanzaro, and Wei Ping. AceReason-Nemotron: Advancing math and code reasoning through reinforcement learning. arXiv preprint arXiv:2505.16400, 2025b.
  7. Ganqu Cui, Lifan Yuan, Zefan Wang, Hanbin Wang, Wendi Li, Bingxiang He, Yuchen Fan, Tianyu Yu, Qixin Xu, Weize Chen, et al. Process reinforcement through implicit rewards. arXiv preprint arXiv:2502.01456, 2025.
  8. Team DeepSeek. DeepSeek-R1-0528 release. https://api-docs.deepseek.com/news/ news250528, 2025. [Released 28-05-2025]. ↗
  9. Team Gemini. Introducing Gemini 2.0: our new AI model for the agentic era. https://blog.google/technology/google-deepmind/ google-gemini-ai-update-december-2024/, 2024. [Released 11-12-2024]. ↗
  10. Team Gemini. Gemini 2.5: Our most intelligent models are getting even better. https://blog.google/technology/google-deepmind/ google-gemini-updates-io-2025/, 2025. [Released 20-05-2025]. ↗
  11. Team Grok. Grok 3 Beta — The age of reasoning agents. https://x.ai/news/grok-3, 2025. [Released 19-02-2025]. ↗
  12. Daya Guo, Dejian Yang, Haowei Zhang, Junxiao Song, Ruoyu Zhang, Runxin Xu, Qihao Zhu, Shirong Ma, Peiyi Wang, Xiao Bi, et al. DeepSeek-R1: Incentivizing reasoning capability in LLMs via reinforcement learning. arXiv preprint arXiv:2501.12948, 2025.
  13. Jujie He, Jiacai Liu, Chris Yuhao Liu, Rui Yan, Chaojie Wang, Peng Cheng, Xiaoyu Zhang, Fuxiang Zhang, Jiacheng Xu, Wei Shen, et al. Skywork open reasoner 1 technical report. arXiv preprint arXiv:2505.22312, 2025.
  14. Jingcheng Hu, Yinmin Zhang, Qi Han, Daxin Jiang, Xiangyu Zhang, and Heung-Yeung Shum. Open-Reasoner-Zero: An open source approach to scaling up reinforcement learning on the base model. arXiv preprint arXiv:2503.24290, 2025.
  15. Naman Jain, King Han, Alex Gu, Wen-Ding Li, Fanjia Yan, Tianjun Zhang, Sida Wang, Armando Solar-Lezama, Koushik Sen, and Ion Stoica. LiveCodeBench: Holistic and contamination free evaluation of large language models for code. In ICLR, 2025.
  16. Jared Kaplan, Sam McCandlish, Tom Henighan, Tom B Brown, Benjamin Chess, Rewon Child, Scott Gray, Alec Radford, Jeffrey Wu, and Dario Amodei. Scaling laws for neural language models. arXiv preprint arXiv:2001.08361, 2020.
  17. Nathan Lambert, Jacob Morrison, Valentina Pyatkin, Shengyi Huang, Hamish Ivison, Faeze Brahman, Lester James V Miranda, Alisa Liu, Nouha Dziri, Shane Lyu, et al. Tulu 3: Pushing frontiers in open language model post-training. arXiv preprint arXiv:2411.15124, 2024.
  18. Hunter Lightman, Vineet Kosaraju, Yuri Burda, Harrison Edwards, Bowen Baker, Teddy Lee, Jan Leike, John Schulman, Ilya Sutskever, and Karl Cobbe. Let’s verify step by step. In ICLR, 2024. — Let's Verify Step by Step
  19. Aixin Liu, Bei Feng, Bing Xue, Bingxuan Wang, Bochao Wu, Chengda Lu, Chenggang Zhao, Chengqi Deng, Chenyu Zhang, Chong Ruan, et al. DeepSeek-V3 technical report. arXiv preprint arXiv:2412.19437, 2024. find
  20. Mingjie Liu, Shizhe Diao, Ximing Lu, Jian Hu, Xin Dong, Yejin Choi, Jan Kautz, and Yi Dong. ProRL: Prolonged reinforcement learning expands reasoning boundaries in large language models. arXiv preprint arXiv:2505.24864, 2025a.
  21. Zichen Liu, Changyu Chen, Wenjun Li, Penghui Qi, Tianyu Pang, Chao Du, Wee Sun Lee, and Min Lin. Understanding R1-Zero-like training: A critical perspective. arXiv preprint arXiv:2503.20783, 2025b.
  22. Michael Luo, Sijun Tan, Roy Huang, Ameen Patel, Alpay Ariyak, Qingyang Wu, Xiaoxiang Shi, Rachel Xin, Colin Cai, Maurice Weber, Ce Zhang, Li Erran Li, Raluca Ada Popa, and Ion Stoica. Deepcoder: A fully open-source 14b coder at o3-mini level. https://pretty-radio-b75.notion.site/DeepCoder-A-Fully-Op… ↗
  23. Michael Luo, Sijun Tan, Justin Wong, Xiaoxiang Shi, William Y. Tang, Manan Roongta, Colin Cai, Jeffrey Luo, Li Erran Li, Raluca Ada Popa, and Ion Stoica. Deepscaler: Surpassing o1-preview with a 1.5b model by scaling rl. https://pretty-radio-b75.notion.site/DeepScaleR-Surpassing-O1-Preview-with-a-1-… ↗
  24. Lachlan McGinness and Peter Baumgartner. Large language models’ reasoning stalls: An investigation into the capabilities of frontier models. arXiv preprint arXiv:2505.19676, 2025. — [arXiv:2505.19676](https://arxiv.org/abs/2505.19676) find
  25. Team Mistral.AI. Stands to reason. Magistral. https://mistral.ai/news/magistral, 2025. [Released 10-06-2025]. ↗
  26. Team OpenAI. Learning to reason with LLMs. https://openai.com/index/ learning-to-reason-with-llms/, 2024. [Released 12-09-2024]. ↗
  27. Team OpenAI. Introducing OpenAI o3 and o4-mini. https://openai.com/index/ introducing-o3-and-o4-mini/, 2025. [Released 16-04-2025]. ↗
  28. Team Qwen. Qwen2.5 technical report. arXiv preprint arXiv:2412.15115, 2024. find
  29. Team Qwen. Qwen3: Think deeper, act faster. qwen3/, 2025. [Released 29-04-2025]. https://qwenlm.github.io/blog/ ↗
  30. Rafael Rafailov, Archit Sharma, Eric Mitchell, Christopher D Manning, Stefano Ermon, and Chelsea Finn. Direct preference optimization: Your language model is secretly a reward model. In NeurIPS, 2023.
  31. John Schulman, Filip Wolski, Prafulla Dhariwal, Alec Radford, and Oleg Klimov. Proximal policy optimization algorithms. arXiv preprint arXiv:1707.06347, 2017. find
  32. Zhihong Shao, Peiyi Wang, Qihao Zhu, Runxin Xu, Junxiao Song, Xiao Bi, Haowei Zhang, Mingchuan Zhang, YK Li, Y Wu, et al. DeepSeekMath: Pushing the limits of mathematical reasoning in open language models. arXiv preprint arXiv:2402.03300, 2024.
  33. Guangming Sheng, Chi Zhang, Zilingfeng Ye, Xibin Wu, Wang Zhang, Ru Zhang, Yanghua Peng, Haibin Lin, and Chuan Wu. HybridFlow: A flexible and efficient RLHF framework. In EuroSys, 2025.
  34. Parshin Shojaee, Iman Mirzadeh, Keivan Alizadeh, Maxwell Horton, Samy Bengio, and Mehrdad Farajtabar. The illusion of thinking: Understanding the strengths and limitations of reasoning models via the lens of problem complexity. arXiv preprint arXiv:2506.06941, 2025.
  35. David Silver and Richard S Sutton. Welcome to the era of experience. Google AI, 2025. find
  36. David Silver, Julian Schrittwieser, Karen Simonyan, Ioannis Antonoglou, Aja Huang, Arthur Guez, Thomas Hubert, Lucas Baker, Matthew Lai, Adrian Bolton, et al. Mastering the game of Go without human knowledge. Nature, 2017. find
  37. Xuerui Su, Shufang Xie, Guoqing Liu, Yingce Xia, Renqian Luo, Peiran Jin, Zhiming Ma, Yue Wang, Zun Wang, and Yuting Liu. Trust region preference approximation: A simple and stable reinforcement learning algorithm for LLM reasoning. arXiv preprint arXiv:2504.04524, 2025. — [arXiv:2504.04524](https://arxiv.org/abs/2504.04524) find
  38. Richard S Sutton, David McAllester, Satinder Singh, and Yishay Mansour. Policy gradient methods for reinforcement learning with function approximation. In NeurIPS, 1999. find
  39. Jonathan Uesato, Nate Kushman, Ramana Kumar, Francis Song, Noah Siegel, Lisa Wang, Antonia Creswell, Geoffrey Irving, and Irina Higgins. Solving math word problems with process-and outcome-based feedback. arXiv preprint arXiv:2211.14275, 2022.
  40. Peiyi Wang, Lei Li, Zhihong Shao, Runxin Xu, Damai Dai, Yifei Li, Deli Chen, Yu Wu, and Zhifang Sui. Math-Shepherd: Verify and reinforce LLMs step-by-step without human annotations. In ACL, 2024.
  41. Yibin Wang, Zhimin Li, Yuhang Zang, Chunyu Wang, Qinglin Lu, Cheng Jin, and Jiaqi Wang. Unified multimodal chain-of-thought reward model through reinforcement fine-tuning. arXiv preprint arXiv:2505.03318, 2025a. — [arXiv:2505.03318](https://arxiv.org/abs/2505.03318) find
  42. Yiping Wang, Qing Yang, Zhiyuan Zeng, Liliang Ren, Lucas Liu, Baolin Peng, Hao Cheng, Xuehai He, Kuan Wang, Jianfeng Gao, et al. Reinforcement learning for reasoning in large language models with one training example. arXiv preprint arXiv:2504.20571, 2025b.
  43. Liang Wen, Yunke Cai, Fenrui Xiao, Xin He, Qi An, Zhenyu Duan, Yimin Du, Junchen Liu, Lifu Tang, Xiaowei Lv, et al. Light-R1: Curriculum SFT, DPO and RL for long CoT from scratch and beyond. arXiv preprint arXiv:2503.10460, 2025.
  44. Colin White, Samuel Dooley, Manley Roberts, Arka Pal, Ben Feuer, Siddhartha Jain, Ravid Shwartz-Ziv, Neel Jain, Khalid Saifullah, Sreemanti Dey, Shubh-Agrawal, Sandeep Singh Sandha, Siddartha Naidu, Chinmay Hegde, Yann LeCun, Tom Goldstein, Willie Neiswanger, and Micah Goldblum. LiveBench: A challen… find
  45. Tian Xie, Zitian Gao, Qingnan Ren, Haoming Luo, Yuqian Hong, Bryan Dai, Joey Zhou, Kai Qiu, Zhirong Wu, and Chong Luo. Logic-RL: Unleashing LLM reasoning with rule-based reinforcement learning. arXiv preprint arXiv:2502.14768, 2025.
  46. Shunyu Yao. The second half. https://ysymyth.github.io/The-Second-Half/, 2025. ↗
  47. Shengyu Ye. EvalHub: All-in-one benchmarking platform for evaluating large language models (LLMs) with comprehensive metrics and standardized testing frameworks. https://github.com/ysy-phoenix/evalhub, 2025. [Accessed 16-06-2025]. ↗
  48. Qiying Yu, Zheng Zhang, Ruofei Zhu, Yufeng Yuan, Xiaochen Zuo, Yu Yue, Tiantian Fan, Gaohong Liu, Lingjun Liu, Xin Liu, et al. DAPO: An open-source LLM reinforcement learning system at scale. arXiv preprint arXiv:2503.14476, 2025.
  49. Yang Yue, Zhiqi Chen, Rui Lu, Andrew Zhao, Zhaokai Wang, Shiji Song, and Gao Huang. Does reinforcement learning really incentivize reasoning capacity in LLMs beyond the base model? arXiv preprint arXiv:2504.13837, 2025.
  50. Weihao Zeng, Yuzhen Huang, Qian Liu, Wei Liu, Keqing He, Zejun Ma, and Junxian He. SimpleRL-Zoo: Investigating and taming zero reinforcement learning for open base models in the wild. arXiv preprint arXiv:2503.18892, 2025.
  51. Qingyang Zhang, Haitao Wu, Changqing Zhang, Peilin Zhao, and Yatao Bian. Right question is already half the answer: Fully unsupervised LLM reasoning incentivization. arXiv preprint arXiv:2504.05812, 2025.
  52. Xinyu Zhu, Mengzhou Xia, Zhepei Wei, Wei-Lin Chen, Danqi Chen, and Yu Meng. The surprising effectiveness of negative reinforcement in LLM reasoning. arXiv preprint arXiv:2506.01347, 2025. find

Updated

↑ back to top

This page in Markdown → https://md.research.elamur.ai/free/en/papers/wen-2025-reinforcement-learning-verifiable-rewards-implicitly/