RSI Arena: Towards Recursive Self-Improvement with Human Feedback
Organizations: Bake AI · University of Notre Dame · University of California, Los Angeles · Stanford University ·
Abstract
Can AI agents autonomously train useful language models and improve them using feedback from users? We introduce RSI Arena, a two-stage study of autonomous post-training as a step toward recursive self-improvement. Ten frontier models act as training agents, each starting from NVIDIA Nemotron 3.5 Lightning 30B-A3B Base. During a six-day first stage, each agent has 1,000 GPU-hours and $300 in API credit on a shared 64-GPU cluster, independently selecting data, implementing training procedures, and choosing checkpoints. We evaluate their models on 20 benchmarks and through blind human evaluations. All ten agents produce working assistants, with the strongest model, trained by GPT-6 Astra, closing a median of 76% of the base-to-Instruct gap across 12 capability benchmarks. Its human-preference rating is also close to NVIDIA Instruct after statistical adjustment for answer length and formatting. In Stage 2, each agent receives the comparison records and votes involving its Stage 1 model and is given three additional days for further training. Using NVIDIA Instruct as a common reference across the two evaluation rounds, we observe an improvement from Stage 1 to Stage 2 in the style-adjusted relative rating of eight of the ten models. We show that benchmark gains were modest, with no clear link to preference gains, while some agents encouraged longer responses and one model showed increased harmful compliance on StrongREJECT. RSI Arena provides an auditable setting for studying how human feedback can guide autonomous model development. It takes a step toward recursive self-improvement with human feedback (RSIHF), in which people help define what improvement means for the AI systems they use.
Figures & tables
| Area | Benchmarks (items) |
|---|---|
| Knowledge and reasoning | GPQA Diamond ( Rein et al., 2024 , 198 questions 8 option orders;) , MMLU-Pro ( Wang et al., 2024 , 12,032;) , SuperGPQA ( M-A-P Team et al., 2025 , 2,000 sampled;) , HLE text only † ( Phan et al., 2025 , 2,158;) , BBEH ( Kazemi et al., 2025 , 4,520;) , AA-Omniscience † ( Jackson et al., 2025 , 600;) |
| Mathematics | AIME 2026 (30) and HMMT February 2026 (33), as run by MathArena ( Balunović et al., 2025 ) |
| Code | LiveCodeBench v6 ( Jain et al., 2025 , 175;) , SciCode ( Tian et al., 2024 , 288 steps of 65 problems;) |
| Long context | AA-LCR † ( Artificial Analysis, 2025 , 100;) , MRCR v2 with 8 needles up to 128k tokens ( OpenAI, 2025b , 485;) |
| Instructions and chat | IFBench ( Pyatkin et al., 2025 , 300;) , Arena-Hard v2 † ( Li et al., 2024b , 504 English prompts;) , MultiChallenge † ( Sirdeshmukh et al., 2025 , 266;) , WildBench v2 † ( Lin et al., 2025 , 1,022;) |
| Safety | StrongREJECT † ( Souly et al., 2024 , 313;) , MASK † ( Ren et al., 2025 , 1,000;) , FORTRESS † ( Knight et al., 2025 , 500 adversarial and 500 benign;) , BBQ ( Parrish et al., 2022 , 5,000 sampled;) |
| Feature | Stage 1 | 95% interval | Stage 2 | 95% interval | Arena.ai |
|---|---|---|---|---|---|
| Answer length (tokens) | 0.169 | −0.036 to 0.370 | 0.394 | 0.242 to 0.559 | 0.249 |
| List items | 0.294 | 0.118 to 0.485 | 0.222 | 0.065 to 0.366 | 0.031 |
| Headers | −0.007 | −0.190 to 0.174 | 0.117 | −0.016 to 0.252 | 0.024 |
| Bold spans | 0.223 | 0.030 to 0.445 | −0.007 | −0.162 to 0.164 | 0.019 |
Appendix figures & tables11 assets
Supplementary material from the paper’s appendix.
Appendix
| Benchmark | Items | Limit | Scoring |
|---|---|---|---|
| GPQA Diamond | 198 8 option orders | 16,384 | final line “Answer: X”; accuracy |
| HLE | 2,158, text only | 16,384 | judge; accuracy |
| MMLU-Pro | 12,032 | 8,192 | official extraction; accuracy |
| SuperGPQA | 2,000, stratified sample | 8,192 | official extraction; accuracy |
| BBEH | 4,520 in 23 tasks | 16,384 | official script; adjusted harmonic mean over tasks |
| AIME 2026 | 30 | 32,768 | MathArena parser; mean accuracy |
| Benchmark | Ours | Published | Source |
|---|---|---|---|
| MMLU-Pro | 81.72 | 81.94 | model card |
| GPQA Diamond (8 samples) | 75.44 | model card | |
| IFBench (loose) | 74.67 | 72.9 | model card |
| SciCode (steps) | 34.03 | 32.6 | model card |
| HLE (text only) | 11.7; 10.6 | model card; Artificial Analysis | |
| AA-LCR | 63.0 | 60.3 | Artificial Analysis |
| Votes | Stage 1 | Stage 2 |
|---|---|---|
| Votes in ordinary battles | 1,685 | 1,444 |
| filtered out | 394 | 125 |
| Accepted votes | 1,291 | 1,319 |
| decisive | 1,003 | 1,002 |
| tie | 159 | 183 |
| both are bad | 129 | 134 |
LLM Agent Self-Improvement
Large language model agent self-improvement studies how agents use experience and feedback to improve their behavior, tools, and workflows.
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