Long-form RewardBench - Writing: leaderboard

Metric: Accuracy (%) on the long-form writing subset of Long-form RewardBench; each item pairs one chosen long-form response (validated by gemini-2.5-pro to beat every rejected one) with three rejected responses, and an item counts as correct only when the reward model ranks the chosen response above all rejected ones (best-of-n); sequence classifiers score each response, generative judges select the best response (Selection mode); higher is better. Source: arxiv.org. Saturation forecast: Estimated already saturated. 22 models tracked.

Top models

#ModelScoreOverall rank
1Claude Opus 4 (20250514)79.4#148
2GPT-4.178.1#240
3Claude 3.5 Sonnet (20240620)72.2#293
4Gemini 2.5 Flash (Preview 04-17)72.2#230
5Claude 3.7 Sonnet (20250219)71.9#196
6GPT-4o (2024-08-06)56.9#326

No result here: #3 Claude Opus 5.5, #5 GPT-6 Astra, #8 Claude Fable 5.1.

Interactive version: theaggregate.ai/benchmark?slug=long-form-rewardbench-writing · How It Works · Data refreshed daily, snapshot 2026-10-11.