Mutual Reasoning Makes Smaller LLMs Stronger Problem-Solvers
FreeSelf-play mutual reasoning to boost small LLMs without fine-tuning
About Mutual Reasoning Makes Smaller LLMs Stronger Problem-Solvers
rStar is a self-play mutual reasoning approach that significantly improves the reasoning capabilities of small language models (SLMs) without requiring fine-tuning or access to superior models. It decouples reasoning into a self-play mutual generation-discrimination process: a target SLM uses Monte Carlo Tree Search augmented with human-like reasoning actions to construct high-quality reasoning trajectories, and another SLM of similar capability acts as a discriminator to verify each trajectory. Only mutually consistent trajectories are considered correct. Experiments across five SLMs show substantial accuracy gains on benchmarks including GSM8K, GSM-Hard, MATH, SVAMP, and StrategyQA—for example, boosting GSM8K accuracy from 12.51% to 63.91% for LLaMA2-7B, from 36.46% to 81.88% for Mistral-7B, and from 74.53% to 91.13% for LLaMA3-8B-Instruct. Code is made available under an open-source license.
Key Features
Pros & Cons
- Significantly improves reasoning accuracy of small LLMs without fine-tuning
- Works with models of similar size; no need for a larger teacher model
- Self-play mechanism leverages mutual consistency to filter correct reasoning paths
- Applicable across multiple model architectures and scales
- Demonstrates large absolute gains (e.g., +51.4% on LLaMA2-7B GSM8K)
- Code is open-source, enabling reproduction and further research