mlsanityData to 14 Oct 2026

REBEL: Reinforcement Learning via Regressing Relative Rewards

arXiv 2404.16767 ↗First posted 25 Apr 2024cs.LG cs.CL cs.CVcited by 69

On the map: LLM alignment / RLHF / preference optimisation → Reward modeling and RLHF

also in 1 more
Abstract (arXiv)

While originally developed for continuous control problems, Proximal Policy Optimization (PPO) has emerged as the work-horse of a variety of reinforcement learning (RL) applications, including the fine-tuning of generative models. Unfortunately, PPO requires multiple heuristics to enable stable convergence (e.g. value networks, clipping), and is notorious for its sensitivity to the precise implementation of these components. In response, we take a step back and ask what a minimalist RL algorithm for the era of generative models would look like. We propose REBEL, an algorithm that cleanly reduces the problem of policy optimization to regressing the relative reward between two completions to a prompt in terms of the policy, enabling strikingly lightweight implementation. In theory, we prove that fundamental RL algorithms like Natural Policy Gradient can be seen as variants of REBEL, which allows us to match the strongest known theoretical guarantees in terms of convergence and sample complexity in the RL literature. REBEL can also cleanly incorporate offline data and be extended to handle the intransitive preferences we frequently see in practice. Empirically, we find that REBEL provides a unified approach to language modeling and image generation with stronger or similar performance as PPO and DPO, all while being simpler to implement and more computationally efficient than PPO. When fine-tuning Llama-3-8B-Instruct, REBEL achieves strong performance in AlpacaEval 2.0, MT-Bench, and Open LLM Leaderboard.

Key facts. Cited by 69 papers in the map (data through 14 Oct 2026). Placed in Reward modeling and RLHF, one of 10 directions in LLM alignment / RLHF / preference optimisation. Builds on 73 of its 122 references that are in the map. First posted on arXiv 25 Apr 2024.

Builds on

73 of 122 references.

Closest ancestors · 13

Same direction, newest first

  1. 2024Dataset Reset Policy Optimization for RLHF12 Apr
  2. 2024Direct Nash Optimization: Teaching Language Models to Self-Improve with General Preferences4 Apr
  3. 2024The N+ Implementation Details of RLHF with PPO: A Case Study on TL;DR Summarization24 Mar
  4. 2024RewardBench: Evaluating Reward Models for Language Modeling20 Mar
  5. 2024A Minimaximalist Approach to Reinforcement Learning from Human Feedback8 Jan
  6. 2023Iterative Preference Learning from Human Feedback: Bridging Theory and Practice for RLHF under KL-Constraint18 Dec
  7. 2023Nash Learning from Human Feedback1 Dec
  8. 2023Is RLHF More Difficult than Standard RL?25 Jun
  9. 2023Direct Preference Optimization: Your Language Model is Secretly a Reward Model29 May
  10. 2023Principled Reinforcement Learning with Human Feedback from Pairwise or K-wise Comparisons26 Jan
  11. 2021WebGPT: Browser-assisted question-answering with human feedback17 Dec
  12. 2019Fine-Tuning Language Models from Human Preferences18 Sep
1 more
  1. 2017Deep reinforcement learning from human preferences12 Jun

Other references · 60

  1. 2021High-Resolution Image Synthesis with Latent Diffusion Modelscited by 18,863
  2. 2022Training language models to follow instructions with human feedbackcited by 15,971
  3. 2017Proximal Policy Optimization Algorithmscited by 15,215
  4. 2021LoRA: Low-Rank Adaptation of Large Language Modelscited by 14,380
  5. 2023Llama 2: Open Foundation and Fine-Tuned Chat Modelscited by 13,028
  6. 2021Training Verifiers to Solve Math Word Problemscited by 10,109
  7. 2023Judging LLM-as-a-Judge with MT-Bench and Chatbot Arenacited by 8,626
  8. 2020Measuring Massive Multitask Language Understandingcited by 7,963
  9. 2018Think you have Solved Question Answering? Try ARC, the AI2 Reasoning Challengecited by 4,886
  10. 2018Soft Actor-Critic: Off-Policy Maximum Entropy Deep Reinforcement Learning with a Stochastic Actorcited by 4,885
  11. 2019HellaSwag: Can a Machine Really Finish Your Sentence?cited by 4,100
  12. 2021TruthfulQA: Measuring How Models Mimic Human Falsehoodscited by 2,975
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  2. 2015Trust Region Policy Optimizationcited by 2,580
  3. 2016Asynchronous Methods for Deep Reinforcement Learningcited by 2,258
  4. 2015High-Dimensional Continuous Control Using Generalized Advantage Estimationcited by 2,026
  5. 2023Consistency Modelscited by 1,822
  6. 2023Pythia: A Suite for Analyzing Large Language Models Across Training and Scalingcited by 1,786
  7. 2023Training Diffusion Models with Reinforcement Learningcited by 982
  8. 2023A General Theoretical Paradigm to Understand Learning from Human Preferencescited by 912
  9. 2024Length-Controlled AlpacaEval: A Simple Way to Debias Automatic Evaluatorscited by 897
  10. 2023Latent Consistency Models: Synthesizing High-Resolution Images with Few-Step Inferencecited by 846
  11. 2021Deep Reinforcement Learning at the Edge of the Statistical Precipicecited by 807
  12. 2019Advantage-Weighted Regression: Simple and Scalable Off-Policy Reinforcement Learningcited by 782
  13. 2017Deep Reinforcement Learning that Matterscited by 754
  14. 2023AlpacaFarm: A Simulation Framework for Methods that Learn from Human Feedbackcited by 748
  15. 2018QT-Opt: Scalable Deep Reinforcement Learning for Vision-Based Robotic Manipulationcited by 743
  16. 2023Aligning Text-to-Image Models using Human Feedbackcited by 422
  17. 2023Efficient Online Reinforcement Learning with Offline Datacited by 363
  18. 2024Direct Language Model Alignment from Online AI Feedbackcited by 260
  19. 2023OpenChat: Advancing Open-source Language Models with Mixed-Quality Datacited by 252
  20. 2022Is Reinforcement Learning (Not) for Natural Language Processing: Benchmarks, Baselines, and Building Blocks for Natural Language Policy Optimizationcited by 246
  21. 2020Implementation Matters in Deep Policy Gradients: A Case Study on PPO and TRPOcited by 186
  22. 2024Preference Fine-Tuning of LLMs Should Leverage Suboptimal, On-Policy Datacited by 185
  23. 2022Hybrid RL: Using Both Offline and Online Data Can Make RL Efficientcited by 161
  24. 2024Stop Regressing: Training Value Functions via Classification for Scalable Deep RLcited by 144
  25. 2023Beyond One-Preference-Fits-All Alignment: Multi-Objective Direct Preference Optimizationcited by 124
  26. 2014Reinforcement and Imitation Learning via Interactive No-Regret Learningcited by 118
  27. 2019Adaptive Trust Region Policy Optimization: Global Convergence and Faster Rates for Regularized MDPscited by 118
  28. 2015Contextual Dueling Banditscited by 101
  29. 2020PC-PG: Policy Cover Directed Exploration for Provable Policy Gradient Learningcited by 92
  30. 2024Human Alignment of Large Language Models through Online Preference Optimisationcited by 91
  31. 2021Of Moments and Matching: A Game-Theoretic Framework for Closing the Imitation Gapcited by 81
  32. 2020VarGrad: A Low-Variance Gradient Estimator for Variational Inferencecited by 75
  33. 2022Nearly Minimax Optimal Offline Reinforcement Learning with Linear Function Approximation: Single-Agent MDP and Markov Gamecited by 55
  34. 2021Efficient First-Order Contextual Bandits: Prediction, Allocation, and Triangular Discriminationcited by 53
  35. 2023Learning to Generate Better Than Your LLMcited by 49
  36. 2023Fine-Tuning Language Models with Advantage-Induced Policy Alignmentcited by 48
  37. 2016Learning to Perform Physics Experiments via Deep Reinforcement Learningcited by 47
  38. 2022Pessimistic Minimax Value Iteration: Provably Efficient Equilibrium Learning from Offline Datasetscited by 44

50 most cited of 60 All 60 (JSON)

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Cited by year (2026 to 14 Oct)

Citing papers per year: 2024: 21; 2025: 28; 2026: 20.

69 papers.

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  1. 2024Self-Play Preference Optimization for Language Model Alignmentcited by 232
  2. 2024Modular Pluralism: Pluralistic Alignment via Multi-LLM Collaborationcited by 113
  3. 2024Exploratory Preference Optimization: Harnessing Implicit Q*-Approximation for Sample-Efficient RLHFcited by 106
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  5. 2025Is Best-of-N the Best of Them? Coverage, Scaling, and Optimality in Inference-Time Alignmentcited by 97
  6. 2024Correcting the Mythos of KL-Regularization: Direct Alignment without Overoptimization via Chi-Squared Preference Optimizationcited by 78
  7. 2024Robust Preference Optimization through Reward Model Distillationcited by 67
  8. 2024Unintentional Unalignment: Likelihood Displacement in Direct Preference Optimizationcited by 67
  9. 2025DeepVideo-R1: Video Reinforcement Fine-Tuning via Difficulty-aware Regressive GRPOcited by 61
  10. 2025All Roads Lead to Likelihood: The Value of Reinforcement Learning in Fine-Tuningcited by 59
  11. 2024The Importance of Online Data: Understanding Preference Fine-tuning via Coveragecited by 55
  12. 2024Offline Regularised Reinforcement Learning for Large Language Models Alignmentcited by 48
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  4. 2024Beyond Bradley-Terry Models: A General Preference Model for Language Model Alignmentcited by 27
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  6. 2025Imbalanced Gradients in RL Post-Training of Multi-Task LLMscited by 20
  7. 2025Direct Alignment with Heterogeneous Preferencescited by 19
  8. 2024Self-Play with Adversarial Critic: Provable and Scalable Offline Alignment for Language Modelscited by 16
  9. 2025Qsharp: Provably Optimal Distributional RL for LLM Post-Trainingcited by 15
  10. 2025Alignment and Safety in Large Language Models: Safety Mechanisms, Training Paradigms, and Emerging Challengescited by 15
  11. 2025Token-Importance Guided Direct Preference Optimizationcited by 14
  12. 2024Aligning Few-Step Diffusion Models with Dense Reward Difference Learningcited by 12
  13. 2024End-to-end Training for Recommendation with Language-based User Profilescited by 10
  14. 2024Faster WIND: Accelerating Iterative Best-of-N Distillation for LLM Alignmentcited by 9
  15. 2024The Central Role of the Loss Function in Reinforcement Learningcited by 8
  16. 2024COMAL: A Convergent Meta-Algorithm for Aligning LLMs with General Preferencescited by 8
  17. 2025Diffusion-Sharpening: Fine-tuning Diffusion Models with Denoising Trajectory Sharpeningcited by 7
  18. 2024Humanizing the Machine: Proxy Attacks to Mislead LLM Detectorscited by 6
  19. 2024Hybrid Preference Optimization for Alignment: Provably Faster Convergence Rates by Combining Offline Preferences with Online Explorationcited by 6
  20. 2025Quantile Reward Policy Optimization: Alignment with Pointwise Regression and Exact Partition Functionscited by 6
  21. 2026Coverage Improvement and Fast Convergence of On-policy Preference Learningcited by 6
  22. 2024Cost-Effective Proxy Reward Model Construction with On-Policy and Active Learningcited by 5
  23. 2025RSPO: Regularized Self-Play Alignment of Large Language Modelscited by 5
  24. 2026Diffusion Reinforcement Learning via Centered Reward Distillationcited by 5
  25. 2026HPSv3++: Scaling Reward Models Across the Full Spectrum of Diffusion Model Capabilitiescited by 5
  26. 2024Unified Preference Optimization: Language Model Alignment Beyond the Preference Frontiercited by 4
  27. 2025Can RLHF be More Efficient with Imperfect Reward Models? A Policy Coverage Perspectivecited by 4
  28. 2025RePO: Understanding Preference Learning Through ReLU-Based Optimizationcited by 4
  29. 2025SquarechiPO: Differentially Private and Robust chi2-Preference Optimization in Offline Direct Alignmentcited by 3
  30. 2025Beyond RLHF: A Unified Theoretical Framework of Alignmentcited by 3
  31. 2025PICACO: Pluralistic In-Context Value Alignment of LLMs via Total Correlation Optimizationcited by 3
  32. 2025MAS2: Self-Generative, Self-Configuring, Self-Rectifying Multi-Agent Systemscited by 3
  33. 2025Why DPO is a Misspecified Estimator and How to Fix Itcited by 3
  34. 2025On the Sample Complexity of Differentially Private Policy Optimizationcited by 3
  35. 2026Reward Models Inherit Value Biases from Pretrainingcited by 3
  36. 2025Refining Few-Step Text-to-Multiview Diffusion via Reinforcement Learningcited by 2
  37. 2026Direct Preference Optimization with Rating Information: Practical Algorithms and Provable Gainscited by 2
  38. 2025Behavior Preference Regression for Offline Reinforcement Learningcited by 1

50 most cited of 69 All 69 (JSON)

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