Let the policy write wrong solutions: negative rollouts beat GRPO by 9.0% on Qwen3-1.7B using only saturated MATH data

shangbinfeng · x · 2026-10-22

Doing RL only on saturated MATH problems (8/8 rollouts correct), asking the policy itself to write a wrong solution and adding it to the group as a negative works best: +9.0% over GRPO on Qwen3-1.7B and +6.4% on 4B, averaged over 8 math, reasoning and IF benchmarks. Negative rollouts beat zero-padding, higher temperature, reward models and irrelevant-info baselines.

Related event: UW Research Recycles Reward-Saturated Data for RL, Boosting Qwen3 by Up to 9 Points(5 posts)→

Original post →

More from Research

Research channel →